BREAKING: Change span statuses for gRPC server spans

[pellared]

Fixes #3110

Changes

The idea behind the PR is to make the spam statuses gRPC convention similar to HTTP semantic conventions.
The gRPC statuses -> HTTP status codes mapping is not anywhere strictly defined.
However, there is are some approximations which can be found:

• grpc/grpc@bb04e07#diff-c94ff143c8f378e6925a985fa18528a8254a6d7fc34bc855e1de13f1e7f3e464
• https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto

I got confused if we should treat INTERNAL as Error for SpanKind.SERVER because of:

• https://github.com/grpc/grpc/blob/master/doc/http-grpc-status-mapping.md
• https://github.com/grpc/grpc-go/blob/a02aae6168aa683a1f106e285ec10eb6bc1f6ded/internal/transport/handler_server.go#L90C8-L92
• https://github.com/grpc/grpc-go/blob/a02aae6168aa683a1f106e285ec10eb6bc1f6ded/internal/transport/http_util.go#L73

On the other hand, the description of INTERNAL says:

Internal errors. This means that some invariants expected by the underlying system have been broken. This error code is reserved for serious errors.

Therefore, I decided to leave it as Error. Also because this is backwards compatible (at least for this gRPC status).

[tigrannajaryan]

LGTM, with one minor comment remaining.

[carlosalberto]

@tigrannajaryan Any opinion on getting this merged for the upcoming April Release?

[tigrannajaryan]

@tigrannajaryan Any opinion on getting this merged for the upcoming April Release?

I think we can merge.

[tigrannajaryan]

@pellared can you resolve the conflicts?

[pellared]

@tigrannajaryan @carlosalberto Done. The PR is ready to be merged 😉