fix(protocol): fix attachment size limit issue when size exceeds uint32

[InJunee]

• Change attachment_size from int32 to int64 in protobuf definitions (baidu_rpc_meta.proto, rpc_dump.proto, nshead_meta.proto)
• Fix type mismatches in ProcessRpcRequest and ProcessRpcResponse:
  • Change req_size/res_size from int to size_t
  • Change body_without_attachment_size from int to size_t
  • Add overflow checks and proper type casting
• Fix size inconsistency in PackRpcHeader and SerializeRpcHeaderAndMeta:
  • Change payload_size parameter from int to size_t
  • Add overflow check for meta_size + payload_size exceeding UINT32_MAX
• Update format strings to use PRId64 and %zu for proper large value display

This fix allows the protocol to correctly handle attachment sizes greater than 4GB (uint32 max), preventing integer overflow and size mismatches.

Fixes #1348

What problem does this PR solve?

Issue Number: resolve

Problem Summary:

What is changed and the side effects?

Changed:

Side effects:

• Performance effects:

• Breaking backward compatibility:

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