Fixes #3312. Mouse API makes it way too hard to track button pressed.

[BDisp]

Fixes

• Fixes Mouse API makes it way too hard to track button pressed #3312

Proposed Changes/Todos

• Add mouse clicked logic for only to raise on the same view that pressed it
• If a mouse button was pressed and grabbed the mouse, the OnMouseEnter isn't ran. Now it run
• Created the ProcessMouseEvent method allowing reuse the code
• Add unit test
• Add hot color for highlight
• Some formatting

Pull Request checklist:

• I've named my PR in the form of "Fixes #issue. Terse description."
• My code follows the style guidelines of Terminal.Gui - if you use Visual Studio, hit CTRL-K-D to automatically reformat your files before committing.
• My code follows the Terminal.Gui library design guidelines
• I ran dotnet test before commit
• I have made corresponding changes to the API documentation (using /// style comments)
• My changes generate no new warnings
• I have checked my code and corrected any poor grammar or misspellings
• I conducted basic QA to assure all features are working

[tig]

I have not had a chance to fully review this, nor run it to see how it works. So I can't comment on whether it works.

But i do not think it actually makes tracking button presses easier, and I do not like aspects of the design. I've commented on those in my code review.