Fixes #3407. Border Subviews

[tig]

Fixes

• Fixes Refactor Border to use subviews for title, lines, and close button #3407

Proposed Changes/Todos

• Todo 1

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]

TextField is drawing over the Border. Clipping problem?

[tig]

TextField is drawing over the Border. Clipping problem?

Please don't look at this yet. It is almost completely broken.