Fixes #5065. Pressing Shift-Alt-T in a TextField causes a t to be entered

[BDisp]

Fixes

• Fixes Pressing Shift-Alt-T in a TextField causes a t to be entered #5065

Proposed Changes/Todos

• I would like to add the kitty addition test lines to reinforce the Key values. Thanks

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

[BDisp]

I don't think anything else needs to be changed. As far as I'm concerned, it's ready for review. Thanks.

[BDisp]

@tig I think you've been having some difficulty getting certain key combinations to work correctly when pressing keys, as some implicit combinations weren't being processed and others weren't being preserved when pressing more keys.

[BDisp]

Still having a bug. I'll fix it.

[BDisp]

I think that all ok now with press and release events.

[BDisp]

@tig you approved before I made a last commit and so I don't know if I can merge this. I'll wait for you say something. Thanks.

[tig]

nicely done!