Fixes #2539. Add feature to draw menus with or without border.

[BDisp]

Fixes #2539 - Menu were already using Frame Border but I added an option to draw without border as well. The hack on the Toplevel was causing some unit tests being fail and I disable it. I also re-enable some unit tests in the MenuTests that was commented before.

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 actually really like this look!!!