feat(rest): Add comprehensive error handling system for REST catalog

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Which issue does this PR close?

• Closes Add comprehensive error handling system for REST catalog #1918.

What changes are included in this PR?

Currently we only have a simple deserialize_unexpected_catalog_error function for errors. Adds a comprehensive error handling system for the REST catalog. Related java implementation is in ErrorHandlers.java.

• Introduce an ErrorHandler Trait.
• Implement specific handlers like NamespaceErrorHandler .
• Implement a unified helper in HttpClient to handle the Async IO and JSON parsing.

Also, I fixed to handle OAuth error response with OAuth-specific error format. OAuth errors currently use a format per RFC 6749:

 {
   "error": "invalid_client",
   "error_description": "Client authentication failed"
 }

This differs from standard REST catalog errors which use:

{
  "error": {
    "message": "...",
    "type": "NoSuchTableException",
    "code": 404
  }
}

So I parses the OAuth error format and converts it to ErrorResponse format for compatibility with error handlers.

Are these changes tested?

unit test, integration test. Currently the integration test only covers the successful cases. After this PR, the failed cases are added.

[HeartLinked]

Hi, I’ve been contributing to iceberg-cpp quite a bit over the past few months, and picked up a ton of experience. This is my first PR for iceberg-rust, and I’m really happy to be part of this awesome community now. Looking forward to the review! @Xuanwo @liurenjie1024 :)