Fixes #2578 - Updates mouse events to be relative to View.Bounds

[tig]

Fixes #2578 - How should MouseEvent work with Margin, Border, and Padding?

• Update docs
• Add more unit tests to enforce current behavior
• Refactor View.ScreenToView/ViewToScreen to be more sensical in the face of Bounds != Frame.
• Update logic that fires mouse events
• Fix View dragging code. Right now, dragging is handled w/in TopLevel. This needs to change to be handled within Border. See #Discuss - There should only be one (Application.Top) #2502. Will define View.Movable and View.Sizable that will control whether a view can be dragged and/or resized.
• Update unit tests to not fail
• Track down and fix all library and Scenario code that depends on old behavior

Related:

• Fixes #2926 - Refactor KeyEvent and KeyEventEventArgs to simplify #2927
• Finish Adornments (master Issue)  #2994

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]

@BDisp & @tznind - still a draft (and currently broken), but I'd love your eyes on this asap.

Thanks!

[tznind]

This looks great. If I understand correctly this PR establishes more clearly the idea of bounds (like view client area) and 'frame' i.e. border, padding margin.

This is good because it simplifies things and is mostly backwards compatible so shouldn't complicate upgrades from v1 too much.

🎆 🚀

[BDisp]

This is really fantastic. Much more clear, more readable. Thanks for effort.

[tig]

I think this is done. I could add more unit tests...

Note the big hack for Toplevel dragging. I decided to not tackle this in this pr but to just hack it until we refactor drag/size per #2537