ci: add new grpc js client stubs generation CI workflow

[sebastiendan]

Description

This PR adds JavaScript client stub generation and packaging in a @topos-network/topos-grpc-client-stub npm package.

Client stubs can then be used in web applications for interactions with the gRPC API of a topos node.

Additions and Changes

• Add package.json and package-lock.json files in the proto directory to identify and version the npm package
• Add a CI workflow to generate stubs and package them in a new package to be published

Note: Packages are built and published on new Github releases. It's important to remember that the version of the package (specified in its package.json file) needs to be updated priori to the creation of the release on Github (otherwise package publication will fail and the release will have to be recreated).

Tagging @Freyskeyd @atanmarko @hadjiszs @gruberb to double-check this point above ⬆️

PR Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added or updated tests that comprehensively prove my change is effective or that my feature works

[codecov]

Codecov Report

Merging #229 (17d4450) into main (d659f92) will decrease coverage by 0.22%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #229      +/-   ##
==========================================
- Coverage   58.74%   58.53%   -0.22%     
==========================================
  Files         171      171              
  Lines        9970     9970              
==========================================
- Hits         5857     5836      -21     
- Misses       4113     4134      +21     

see 4 files with indirect coverage changes

[Freyskeyd]

For the version, we could manage that using a release manager on an xtask project