[SPARK-44681] Fix issues when writing Go application code using Spark Connect Go client library

[hiboyang]

What changes were proposed in this pull request?

When trying to write Go application code using Spark Connect Go client and put the Go application code in users' own repo (e.g. https://github.com/user-foo/my-go-application), the Go application code cannot resolve Spark Connect Go client from https://github.com/apache/spark-connect-go correctly, due to two issues:

1. The name github.com/apache/spark-connect-go/v_3_4 cannot resolve correctly to find the module, it complains not finding go.mod file under github.com/apache/spark-connect-go/v_3_4. After change the name to github.com/apache/spark-connect-go/v34, it is good.

2. The Go application code needs generated Go protobuf code as well. Thus need to commit the generated Go protobuf code into github.com/apache/spark-connect-go repo.

Why are the changes needed?

See above.

Does this PR introduce any user-facing change?

No.

How was this patch tested?

Tested by run Go application code to use Spark Connect Go client.

[hiboyang]

@HyukjinKwon @grundprinzip @zhengruifeng I find some issues when I write a standalone Spark Connect application using this spark-connect-go repo as a library. The PR is to fix these issues.

[hiboyang]

This PR is mostly generated code like internal/generated/base.pb.go, internal/generated/base_grpc.pb.go, etc. We need to put those files into this repo so other Go application could reference this repo as a Go library properly.

Please ignore those generated code. Except those code, the PR is actually small :)

[grundprinzip]

it's interesting that this hasn't caused issues before really. But I'm fine with the changes.

[hiboyang]

Thanks for reviewing! Yeah, previously we have code inside this repo referencing this same library , thus v_3_4 does not cause problem. When I wrote another Go application outside of this repo, referencing this repo as a library, then got issue.

[zhengruifeng]

merged to master