rename interfaces Go packages with a "proto" suffix

[battlmonstr]

This depends on erigontech/interfaces#216

What's changed:

• added "proto" suffix to packages and generated folders (I've tried to keep folder names unchanged, but it was problematic for tooling)
• in the erigon code update package import paths, but keep them aliased to previous names such that it doesn't lead to massive code churn. We can do the code changes separately in subsequent PRs. Each code owner will do it for them.
• had to update make grpc command: tried various --go_opt=paths=xxx (see https://protobuf.dev/reference/go/go-generated/ ), but it still generated wrong namespaces, so had to list each of them separately

[battlmonstr]

@AskAlexSharov Thanks for review. Do you have an open PR that makes erigon compatible with erigontech/interfaces#213 ? Could you tag me on it so that I follow it up when it is merged?

[AskAlexSharov]

@AskAlexSharov Thanks for review. Do you have an open PR that makes erigon compatible with ledgerwatch/interfaces#213 ? Could you tag me on it so that I follow it up when it is merged?

Giulio reverted this PR: erigontech/interfaces#214 - we just didn't merge