[SPARK-43895] Basic Repository Layout

[grundprinzip]

Proposed Changes

In order to prepare the implementation of the Go client. This patch prepares the repository layout.

• Adds the git submodule for the Spark repository, currently pointing at master for the reference to the proto files.
• Adds the Makefile and the necessary outline for the build system
• Adds the buf generation logic for the protos.

Testing

make gen && make check && make test

[zhengruifeng]

Is it possible to make apache/spark a submodule so that we don't need to copy the proto files?

[grundprinzip]

Actually, I was looking at the submodule and found it too clunky, tried again and it's working quite nice, will change.

[grundprinzip]

@zhengruifeng @HyukjinKwon this PR should be good now and the last PR before we can bring in the changes of Bo for the base client. The next step would be adding the workflow integration.

[HyukjinKwon]

qq, did you write this Makefile? or get it from somewhere?

[grundprinzip]

I wrote this.

[HyukjinKwon]

Merged to master.

[grundprinzip]

Thanks for merging