inconsistent protobuf structure definition between rpcRequestMeta and brpc protobuf

https://github.com/baidu/Jprotobuf-rpc-socket/blob/master/jprotobuf-rpc-core/src/main/java/com/baidu/jprotobuf/pbrpc/data/RpcRequestMeta.java
```
/** 分布式追踪 Parent Span ID. */
@Protobuf(order = 6)
private Long parentSpanId;

/** 扩展字段. */
@Protobuf(order = 7)
private List extFields;

/** 非PbRpc规范，用于传输额外的参数. */
@Protobuf(fieldType = FieldType.BYTES, order = 110)
private byte[] extraParam;
```

https://github.com/apache/brpc/blob/master/src/brpc/policy/baidu_rpc_meta.proto
```
message RpcRequestMeta {
required string service_name = 1;
required string method_name = 2;
optional int64 log_id = 3;
optional int64 trace_id = 4;
optional int64 span_id = 5;
optional int64 parent_span_id = 6;
optional string request_id = 7; // correspond to x-request-id in http header
optional int32 timeout_ms = 8; // client's timeout setting for current call
}
```

when will jprotobuf rpc support set request id and timeout to rpc request?

Start with jprotobuf-rpc-core/src/main/java/com/baidu/jprotobuf/pbrpc/data/RpcRequestMeta.java and compare its field definitions with brpc/src/brpc/policy/baidu_rpc_meta.proto. Trace how RpcRequestMeta is serialized, then determine how request_id and timeout_ms should be represented without breaking existing field numbering. Done means both values are supported consistently with the brpc structure.

Written by the indexing model from the issue text.