Generate grpc/pb with commonjs_strict

[niloc132]

This enables applications to load more than one version of the JS API as ES6 modules, without the implementations interfering with each other. Unfortunately, the JS protoc plugin doesn't support this case well, so workarounds are required to correctly reference proto files that use packages.

Fixes #5318

[mattrunyon]

I just pulled and built this (w/ prepareCompose) and see a proto.google.protobuf.Timestamp in global still. Seems that's the only thing on the global proto at least

[niloc132]

Thanks - that's part of the root bug, that even the built-in protoc-js-gen doesn't correctly support commonjs_strict for its own generated files. See protocolbuffers/protobuf-javascript#25.

The good news is that we don't actually use that package or its message types at all presently, so we can't run into this bug with them. If that changes, we're going to need to entirely give up on the existing codegen.

[mattrunyon]

Checked locally and the only thing in global now is proto.google.protobuf.Timestamp, but as @niloc132 noted we don't use this.

Ran web e2e tests against this branch and they passed.

Didn't check that the TS gen worked properly, so if that works then this looks good to me