[Bug]: Query for txs by events containing <= returns invalid element

[rootulp]

Summary of Bug

Previously, querying for transactions based on events with <= or >= worked. On cosmos-sdk v0.46.13 it doesn't. See celestiaorg/celestia-app#2098 (comment)

Version

celestia-app is on cosmos-sdk v0.46.13. My hypothesis is that this hasn't worked since cosmos-sdk v0.46.4 because that appears to be the first release with #12474

Steps to Reproduce

1. Install celestia-app v1.0.0-rc9
2. Run celestia-app with the API enabled (i.e. celestia-appd start --api.enable)
3. Query for a transaction with a range

$ curl http://localhost:1317/cosmos/tx/v1beta1/txs?events=tx.height%3C=10

Note: %3C is < URL escaped

Observed behavior

{
"code": 3,
"message": "invalid event; event tx.height\u003c=10 should be of the format: {eventType}.{eventAttribute}={value}",
"details": [
]
}%

Expected behavior

A list of transactions that happened in block height <= 10

Notes

A failing test case exists at rootulp@90b7d5f

[rootulp]

A fix in the downstream celestiaorg fork: celestiaorg#331 and a fix in this repo: #16994