Add wide character rendering repro app for terminal bug reports

[tig]

Fixes

• N/A (new utility, no issue)

Proposed Changes/Todos

Adds a minimal standalone console app (Examples/WideCharRepro/) that demonstrates incorrect wide/fullwidth Unicode character rendering in terminal emulators. This is intended as a repro to attach when filing bugs against terminals that mishandle wide characters (emoji, CJK, fullwidth forms).

The app outputs 5 tests:

1. Emoji grid with box-drawing separators
2. CJK Ideograph grid
3. Mixed narrow + wide content with exact column math
4. Diverse wide-char grid (emoji, animals, CJK)
5. Column-alignment verification (X markers at column 20)

If the | separators are not vertically aligned, the terminal has a wcwidth bug.

Also includes:

• README.md -- explains the problem, how to run, and relevant Unicode standards
• BUG_REPORT_TEMPLATE.md -- copy-paste template for filing issues against terminals, with a compatibility matrix

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
• 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

[chatgpt-codex-connector]

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[BDisp]

I haven't had the opportunity to review this PR. I'm just asking if the use of ZWJ emojis was carefully considered, as it's also considered a wide character occupying two columns?

[tig]

I haven't had the opportunity to review this PR. I'm just asking if the use of ZWJ emojis was carefully considered, as it's also considered a wide character occupying two columns?

sorry, but I needed to merge to move on and since its' just as sample...

I just used codepoints that demonstrated the Github Copilot App terminal bug:

github/app#433

If you think this test app can be improved, that'd be awesome!