Build Helm from source

[abrisco]

This would make it easier to test changes to upstream helm that would benefit Bazel environments. Ideally this would be another module in https://github.com/bazelbuild/bazel-central-registry but could also be some BUILD files that live in this repo.

[abrisco]

Helm rejected Bazel integration (helm/helm#6557) which I think is the right call but it would still be useful for the Bazel community to maintain some integration.