Add libpak-tools package bundle command which builds and packages a buildpack

[dmikusa]

Summary

This command runs the build workflow for libcnb & libpak based buildpacks. It both compiles (libpak-tools package compile) and also packages the compiled buildpack into a buildpack image which is loaded into the Docker daemon.

It does not presently work for non-libcnb/libpak buildpacks because they have a slightly different build system, and specifically the way that the version number is set differs. This can be worked around, but requires a separate PR to libcnb to update the compilation command and how it handles setting the version number.

This tool is build off libpak v2, but should work with libpak v1 buildpacks as well.

Use Cases

An easy way to compile & package libcnb & libpak buildpacks.

Checklist

• I have viewed, signed, and submitted the Contributor License Agreement.
• I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• I have added an integration test, if necessary.
• I have reviewed the styleguide for guidance on my code quality.
• I'm happy with the commit history on this PR (I have rebased/squashed as needed).

[dmikusa]

Rebased.

I'm a little unsure about these go.work and go.work.sum files. That is something VScode suggested I do, but it didn't seem to cause issue if I did not do that either. I think it's necessary because of the tools/ sub-directory which has tools for running the linter and building. Maybe there's a better way to do this all? They are really just dev dependencies, but I'm not 100% sure how to do that in Go.

If you think I should look into this more before we merge, let me know.

[pivotal-david-osullivan]

I had a look at these files and I read they're not intended to be checked in? golang/go#51941 (comment)

[dmikusa]

@pivotal-david-osullivan Interesting. OK, removed. If it becomes annoying, we can add them later.