Fix TextEdit breakpoint hover not hiding on mouse exit

[kitbdev]

• Fixes The breakpoint hover indicator doesn't overlap with its click detection #65517

The area below the last line is no longer part of the last line's gutter.
The hovering, mouse cursor shape, and clicking gutter now uses the same logic.
Updating the gutter (add/remove/change size) now immediately updates the hover as well.
Added some gutter hover and click tests.

[MewPurPur]

Reviewed the code and tested the changes, it all looks good.

I see breakpoints left behind all the time now when using the code editor, so I think it would be a good idea to merge this during beta to clear up this jank for 4.4

[kitbdev]

Removed the CodeEdit mouse exit redraw, I don't think anything else was relying on it and I didn't notice any issues.

I don't think this can be cherry-picked. The breakpoint indicator did hide during 4.1 to 4.3 from #78509, it was just recently re-introduced in #65517.
This PR also relies on the changes #65517 made for the breakpoint hover, so without it this also may not fix the click logic and hover logic being different.

[syntaxerror247]

Removed cherrypick labels due to the reason mentioned by @kitbdev in above comment.

[Calinou]

Tested locally, it works as expected. I made sure this doesn't cause unnecessary redraws.

Code looks good to me.

[Repiteo]

Thanks!