Reorganize linters and fixers

[queengooborg]

This PR reorganizes the linters and fixers structure, as discussed in the last BCD meeting. This places all of the fixer scripts under the same folder that the linters are, and renames the folder from test/ to lint/.

This ensures both better organization and prepares for a potential linter overhaul in the future.

[Elchi3]

Why was this merged without review?

[queengooborg]

We had agreed to do this during the BCD call on March 12th. I didn't think this would require review since it is solely reorganizing internal infrastructure.

I see this had created merge conflicts for one of your PRs, though. Apologies for that -- happy to fix that right away!

[Elchi3]

It would have been useful to still review in more details. In meetings we usually only assess if a PR makes sense generally, ie. if we agree with the notion of it and/or general direction.

These file names seem not ideal:

test-browsers-data.ts
test-browsers-presence.test.ts

Why not omit the first "test"?
browsers-data.ts
browsers-presence.test.ts

[queengooborg]

That's a fair point. I figured that this particular change was straightforward enough that it wouldn't need a thorough technical review.

The filenames for the linters is something that I've also been wanting to update to remove the redundant test- prefix, but I figured that would be better to do in another PR since that had a stronger likelihood of creating merge conflicts with other PRs. (Turns out that the open linter-related PRs all had merge conflicts anyways...!)