Fix: Resolve CJK Enhanced UI conflict in Windows nav mode

[surfer0627]

Summary of the issue

When this add-on is in Windows navigation mode, some numpad keys may stop working right if CJK Enhanced UI is also installed.
This can happen because both add-ons try to use some of the same keys. Then numpad 1, 2, 3, and Shift+numpad2 may stop acting like End, Down Arrow, Page Down, and Shift+Down Arrow.

User facing changes

• Added a small fix for CJK Enhanced UI compatibility.
• In Windows navigation mode, the known conflicting numpad keys work as expected.
• When switching back to NVDA navigation mode, the extra mappings are removed.

Developer facing changes

• Added a small CJK compatibility mapping list.
• Added a helper to check whether CJK Enhanced UI is running.
• Added a helper to add or remove the compatibility mappings.

Development approach

• Added the CJK fix as a small helper.
• Called that helper when entering and leaving Windows navigation mode.
• Left the main mode-switching flow unchanged.

Testing Steps

1. Download the numpadNavMode try build).
2. Install it.
3. Download the CJK Enhanced UI add-on.
4. Install it.
5. Restart NVDA.
6. Press NVDA+Alt+NumpadPlus to switch to Windows navigation mode.
7. Press Numpad 1, 2, 3, and Shift+Numpad 2.
8. Check that they work like End, Down Arrow, Page Down, and Shift+Down Arrow.
9. Switch back to NVDA navigation mode.
10. Check that the CJK Enhanced UI key bindings work normally again.

Known issues with pull request:

None.

Credit

This approach was based on a suggestion from a community developer who gave permission for it to be reused, but asked not to be named. We appreciate their contribution.

[surfer0627]

CC @josephsl,
I would appreciate your review on this PR when you have time.
The changes mainly address:
• Fix for key conflict issue: This PR resolves a known key conflict between Numpad Nav Mode and the CJK Enhanced UI add-on.
Please let me know if any adjustments are needed.
Thanks.

[XLTechie]

@surfer0627 thank you for this contribution. I or @josephsl will look it over next week.

[surfer0627]

Thanks @XLTechie and josephsl .