Add settings for changing the workbench font size and font

[ElijahPepe]

This PR fixes #519.

This does need to be refined a bit; I did this rather hastily.

[ghost]

All CLA requirements met.

[ElijahPepe]

This PR adds the settings necessary for setting a font size and font family for the workbench and applies it in themeing.ts. I'm not sure if anything else is necessary like watching for changes to the settings and applies them retroactively.

[ElijahPepe]

@sbatten, any word?

[bpasero]

Same discussion starting from #63602 (comment) applies here again.

[ElijahPepe]

Same discussion starting from #63602 (comment) applies here again.

Ah, okay, I see the issue. I will attempt to find as many instances as I can of certain pixel values being hardcoded and alter them.

[ElijahPepe]

I think I got all of the hardcoded values, but I'm not entirely sure.

[ElijahPepe]

Tests should be green now.

[laurentlb]

The PR is very large. I wonder if maintainers are more likely to accept it if we split the PR:

• A first PR that does the safe refactor-only changes (pass IConfigurationService around).
• A 2nd PR that replaces the constants with the computed sizes.

If the first PR is merged and the 2nd PR is small enough, my team at Google can help test it and iterate on it.

[ElijahPepe]

@laurentlb I'm happy to split this PR. How would you like to open up communication for that?

[ElijahPepe]

I'm going to close this for now while @laurentlb and I work towards splitting this PR up and getting changes made through at a much slower and more deliberate pace.

[isidorn]

@ElijahPepe @laurentlb thanks for doing that. Please ping me on any new PRs you open.