Replace Mapbox with MapLibre across the code base

[wipfli]

Should we replace Mapbox with MapLibre across the code base? This would probably lead to breaking changes in all platforms so we might want to bundle that with other breaking changes...

[hy9be]

Took a look today and found 2k+ Mapbox occurrences in *.cpp files. I suggest we make a phased plan and replace them incrementally.

Btw, @wipfli is there a way for me to know our current test coverage? High test coverage should make changes like this less daunting.

[wipfli]

I don't know how to measure the test coverage. But currently we are not running render and query tests in CI, see #350. These tests helped us a lot to find bugs in the TypeScript migration in GL JS.

[hy9be]

I have "integrating with codecov" on my plan. Will prioritize it after solving more burning issues (e.g. CI with Apple Silicon runners, and updating the documentation)