Include Zephyr third-party modules via library

[beriberikix]

I'm experimenting with integrating Golioth. The simple path would be to include it in the top-level west.yml but has its downsides (ex. will need wait to merge; not scalable for the project.)

Is there some clever way import projects as modules so that they can be used as part of the library?

Said differently - is there a recommended path to create Arduino libraries that are essentially C++ wrappers with Arduino-flavored APIs that are based on existing Zephyr modules?