protobuf.js

Caveats

Fails to generate test_messages_proto2.proto because of extensions with groups, causing all proto2 tests to fail.
Cannot generate code for Editions.
Does not provide a standard code generator plugin. That's why we run the pbjs and pbts commands to generate code instead of buf or protoc.
TypeScript must be configured with skipLibChecks: true because of a mismatch between generated interface and generated class, see this issue for more context.
Generated imports are incorrect for static-module and es6. A custom wrapper is used in accordance with the pbjs docs. See this issue for more details.