Bad http status and error message on wrong payload

[irevoire]

Describe the bug
When sending badly formatted payload to meilisearch it returns a « 500 internal error » instead of a user error.
The error message is also quite ugly.

To Reproduce
Steps to reproduce the behavior:
1.echo "kefir" | http PUT :7700/indexes/12/documents "Content-Type: application/json" "Content-Encoding: gzip"
2.

HTTP/1.1 500 Internal Server Error
content-encoding: gzip
content-type: application/json
date: Thu, 13 Jun 2024 14:31:37 GMT
transfer-encoding: chunked
vary: Origin, Access-Control-Request-Method, Access-Control-Request-Headers
vary: accept-encoding

{
    "code": "internal",
    "link": "https://docs.meilisearch.com/errors#internal",
    "message": "payload reached EOF before completing: Some(Custom { kind: Other, error: DecompressError(General { msg: None }) })",
    "type": "internal"
}

[Karribalu]

Hey @irevoire,

I opened PR #4716 for this fix, but I don't see my changes affecting any tests. However, I am seeing some random test failures. Can you please guide me on whether my changes are related to any other tests?

Thank you!