FoxVox Update v3.9.2

Changelog:

• Fix issue with Page Up/Down, End, and other special keys not capturing correctly on output record.
• Add filter to output keys list.
• Add 'Duplicate' option to command group context menus.
• Remove 'Remove Sound' option from key command groups where it doesn't apply.
• Pin duplicated command groups on creation to match commands.
• Restructure and cleanup parts of code base for future maintenance (no logic changes, just organization).

This is a simple maintenance update which also addresses a few minor issues.