feat: add proxy monerod resiliency (#6637)

Description
---
Added resiliency to the merge mining proxy monerod connection:
- At startup if the `monero.fail` is not available
- With the default list of monerod servers (it is not necessary anymore
to populate the list in `config.toml` or from the command line)
- When qualifying the starting list of monerod servers
- When getting the fully qualified monerod URL to send requests to
during runtime

Motivation and Context
---
All the things addressed in this PR were handled inadequately.

How Has This Been Tested?
---
- Added unit tests.
- System-level testing:
  - Start the merge mining proxy using the default config. **[PASSED]**
- Start the merge mining proxy where `use_dynamic_fail_data = false`.
**[PASSED]**
- Start the merge mining proxy where `use_dynamic_fail_data = true` but
`monero_fail_url` is invalid. **[PASSED]**
- Start the merge mining proxy where `use_dynamic_fail_data = false`
with 5 entries in the `monerod_url` list but where the first 4 entries
are invalid. **[PASSED]**
- Perform a merge mining proxy + monerod stress test by issuing json rpc
commands to the proxy that needs responses from the monerod server,
testing multiple access paths into `match inner.handle(&method_name,
request).await {`, all of this while merge mining is taking place.
**[PASSED]**

Stress test results

```
method: get_height, tick: 1.00s
  1: method: get_height; time now: 07:41:12.966; duration: 354.83ms, response length: 124
  2: method: get_height; time now: 07:41:14.976; duration: 367.71ms, response length: 124
  3: method: get_height; time now: 07:41:16.974; duration: 360.16ms, response length: 124
  4: method: get_height; time now: 07:41:18.976; duration: 354.45ms, response length: 124
  5: method: get_height; time now: 07:41:20.990; duration: 373.91ms, response length: 124
  ...
method: get_version, tick: 1.00s
  1: method: get_version; time now: 07:41:22.963; duration: 355.97ms, response length: 686
  2: method: get_version; time now: 07:41:25.003; duration: 378.83ms, response length: 686
  3: method: get_version; time now: 07:41:26.978; duration: 369.92ms, response length: 686
  4: method: get_version; time now: 07:41:28.978; duration: 362.31ms, response length: 686
  5: method: get_version; time now: 07:41:30.979; duration: 358.23ms, response length: 686
  ...
method: get_block_template, tick: 1.00s
  1: method: get_block_template; time now: 07:41:33.023; duration: 408.98ms, response length: 1490
  2: method: get_block_template; time now: 07:41:35.007; duration: 388.51ms, response length: 1490
  3: method: get_block_template; time now: 07:41:37.002; duration: 388.86ms, response length: 1490
  4: method: get_block_template; time now: 07:41:39.005; duration: 386.01ms, response length: 1490
  5: method: get_block_template; time now: 07:41:41.018; duration: 410.48ms, response length: 1490
  ...
```


![image](https://github.com/user-attachments/assets/9393ebc5-8b2b-41b5-88c9-58aaf38ce143)


![image](https://github.com/user-attachments/assets/59b922ba-0c73-4070-bf77-24cbb5310ee3)

What process can a PR reviewer use to test or verify this change?
---
- Code review
- System-level testing as above

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Breaking Changes
---

- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

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<!-- BREAKING CHANGE: Description what the user should do, e.g. delete a
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applications/minotari_merge_mining_proxy/Cargo.toml

@@ -42,6 +42,7 @@ hex = "0.4.2"
 hyper = { version ="0.14.12", features = ["default"] }
 jsonrpc = "0.12.0"
 log = { version = "0.4.8", features = ["std"] }
+markup5ever = "0.11.0"
 monero = { version = "0.21.0" }
 reqwest = { version = "0.11.4", features = ["json"] }
 serde = { version = "1.0.136", features = ["derive"] }
@@ -57,5 +58,4 @@ scraper = "0.19.0"
 tari_features = { path = "../../common/tari_features", version = "1.7.0-pre.2" }
 
 [dev-dependencies]
-markup5ever = "0.11.0"
 hyper = { version ="0.14.12", features = ["full"] }

applications/minotari_merge_mining_proxy/src/config.rs

@@ -104,7 +104,40 @@ impl Default for MergeMiningProxyConfig {
             override_from: None,
             use_dynamic_fail_data: true,
             monero_fail_url: MONERO_FAIL_MAINNET_URL.into(),
-            monerod_url: StringList::default(),
+            monerod_url: StringList::from(vec![
+                "http://node.c3pool.org:18081".to_string(),
+                "http://xmr-full.p2pool.uk:18089".to_string(),
+                "http://monero.stackwallet.com:18081".to_string(),
+                "http://xmr.support:18081".to_string(),
+                "https://xmr-01.tari.com".to_string(),
+                "http://node1.xmr-tw.org:18081".to_string(),
+                "http://monero-g2.hexhex.online:18081".to_string(),
+                "http://137.220.120.19:18089".to_string(),
+                "http://185.218.124.120:18489".to_string(),
+                "http://185.218.124.120:18789".to_string(),
+                "https://xmr-de-2.boldsuck.org:18081".to_string(),
+                "http://46.32.46.171:18081".to_string(),
+                "http://185.218.124.120:18089".to_string(),
+                "http://185.218.124.120:18589".to_string(),
+                "http://xmr-de-1.boldsuck.org:18081".to_string(),
+                "http://185.218.124.120:18889".to_string(),
+                "http://pinodexmr.hopto.org:18081".to_string(),
+                "http://node.tincloud.eu:18081".to_string(),
+                "http://183.6.24.33:18081".to_string(),
+                "http://147.45.196.232:18089".to_string(),
+                "http://h-helix.com:18089".to_string(),
+                "http://185.218.124.120:18689".to_string(),
+                "http://185.218.124.120:18289".to_string(),
+                "https://node.tincloud.eu".to_string(),
+                "https://xmr-de.boldsuck.org:18081".to_string(),
+                "https://monero.booze.org".to_string(),
+                "https://xmr.mailia.be:18088".to_string(),
+                "https://xmr.lolfox.au".to_string(),
+                "https://xmr1.doggett.tech:18089".to_string(),
+                "https://node.icefiles.nz:18081".to_string(),
+                "http://45.8.132.220:18089".to_string(),
+                "http://82.147.85.13:18089".to_string(),
+            ]),
             monerod_username: String::new(),
             monerod_password: String::new(),
             monerod_use_auth: false,

applications/minotari_merge_mining_proxy/src/error.rs

@@ -96,10 +96,10 @@ pub enum MmProxyError {
     InvalidHeaderValue(#[from] InvalidHeaderValue),
     #[error("Block was lost due to a failed precondition, and should be retried")]
     FailedPreconditionBlockLostRetry,
-    #[error("Could not convert data:{0}")]
+    #[error("Could not convert data: {0}")]
     ConversionError(String),
-    #[error("No reachable servers in configuration")]
-    ServersUnavailable,
+    #[error("No reachable servers in configuration: {0}")]
+    ServersUnavailable(String),
     #[error("Invalid difficulty: {0}")]
     DifficultyError(#[from] DifficultyError),
     #[error("TLS connection error: {0}")]