Fixes #3793. Simplifies and makes correct KeyDown/Up API, Fixes: CollectionNavigator should be called on KeyDown

[tig]

Fixes

• Fixes Pressing 'c' in UICatalog does not move to 'Colors' category #3793
• Partially addresses (for keyboard events): Refactor and align event handling with common/best practices #3209
• Partially addresses Command is too tightly coupled with KeyBindings #3778

Proposed Changes/Todos

• Refactor View.OnKeyDown/Up to use proper event patterns and simplify
• Simplify Application.KeyDown handling
• Git rid of unused and unneeded InvokingKeyBindings event.
• Fix ListView, TableView, and TreeView to use correct events
• Fix associated unit tests
• Update API docs, fix keyboard.md, and add events.md

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