Split repository into multiple packages

[kellnerd]

The code under utils/ and tools/ can be used independently from the rest of the MB specific code, so it would make sense to move these directories into separate Node.js packages and git repos.

• [x] tools: moved to https://github.com/kellnerd/userscript-bundler
• [x] utils: moved to https://github.com/kellnerd/es-utils
• [ ] src/types/MBS ? alternatively use https://github.com/rinsuki-lab/typedbrainz ?

Related conversation on IRC: https://chatlogs.metabrainz.org/libera/musicbrainz/msg/5159137/