WebSocket: enable support for per-message compression

[scottinet]

Description

Closes #1734

This PR enables per-message compression for websocket connections.

To do this, this PR replaces the ws module with the uWebSockets.js one: the latter is faster, more stable, and not prone to the catastrophic memory fragmentation issue with Node.js (mitigated in later Node.js 12.x versions).

Since µwebsockets uses C sockets, we cannot replace the WebSocket layer without replacing the HTTP one too: we cannot reuse the Node.js HTTP socket for WebSocket, and we don't want Kuzzle to have 2 different network ports for HTTP and WebSocket.
So this PR also lets µws handle HTTP connections, hence the sizeable refactor.

Enhancements

• The allow-encoding HTTP header is now properly interpreted: before this PR, the priority argument <algorithm>;q=<priority> was ignored
• Content parsing for multipart form requests is now done by µws, letting us remove the busboy dependency
• Due to how µws handles idle client connections and heartbeat, I had to rework the websocket options in our RC file:
  • the heartbeat option is now deprecated and ignored
  • the idleTimeout now cannot be deactivated, and its value cannot be set lower than 1000ms. To prevent breaking changes with existing installs, this option is defaulted to 60000ms if set to a value lower than 1000.
  • a new compression option has been added. It takes a boolean (false by default): setting this option to true enables per-message compression
• Add a configurable rate limiter for websocket connections (disabled by default)

Other changes

• Debug domain for the network layer has been renamed kuzzle:network:* (from kuzzle:entry-point:*)
• The server:getConfig removed the entire http configuration from its output, instead of just the HTTP routes one (http.routes). This has been fixed, as not returning the http config is a bit confusing (I know I was perplexed when trying to figure why I didn't have HTTP config in that route output)
• Default timeout of cucumber.js has been increased from 5000ms to 30000ms, to prevent functional tests to fail in github actions

Bug fixes

• Numbers as raw request results are now correctly handled (trying to send a number as a raw response results in an error without this PR)
• Make a realtime functional test (using the functional tests plugin) reentrant, allowing it to be run multiple times on the same node

[codecov]

Codecov Report

Merging #2029 (2415016) into 2-dev (e8d582a) will decrease coverage by 0.19%.
The diff coverage is 93.79%.

❗ Current head 2415016 differs from pull request most recent head 1e43ad3. Consider uploading reports for the commit 1e43ad3 to get more accurate results

@@            Coverage Diff             @@
##            2-dev    #2029      +/-   ##
==========================================
- Coverage   93.77%   93.58%   -0.20%     
==========================================
  Files         123      122       -1     
  Lines        7586     7589       +3     
==========================================
- Hits         7114     7102      -12     
- Misses        472      487      +15     

Impacted Files	Coverage Δ
lib/api/controllers/serverController.js	92.40% <0.00%> (ø)
lib/api/funnel.js	96.24% <ø> (ø)
lib/config/default.config.js	100.00% <ø> (ø)
lib/core/network/protocols/protocol.js	86.36% <ø> (-4.27%)	⬇️
lib/kuzzle/kuzzle.js	75.52% <0.00%> (-1.08%)	⬇️
lib/config/index.js	95.31% <90.00%> (-2.42%)	⬇️
lib/core/network/protocols/httpMessage.js	94.44% <94.44%> (ø)
lib/core/network/protocols/httpwsProtocol.js	95.14% <95.14%> (ø)
lib/core/network/context.js	100.00% <100.00%> (ø)
lib/core/network/entryPoint.js	97.89% <100.00%> (-0.08%)	⬇️
... and 6 more

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[Aschen]

Welcome back uWS 🎉

[scottinet]

@Aschen > I applied your requested changes.

[scottinet]

@Leodau > changes applied.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication