DisabledFormattingAccelerators.All doesn't disable all accelerators

### Describe the bug

Setting `RichEditBox.DisabledFormattingAccelerators` to `All` leaves a lot of accelerators still enabled

### Steps to reproduce the bug

1. Add a `RichEditBox` to your UI and set `DisabledFormattingAccelerators` property to `All`
2. Press `Ctrl+Shift+A`
3. Type something
4. Notice the text being rendered all caps

Same happens with dozen more shortcuts

### Expected behavior

All text format accelerators are disabled, leaving base text shortcuts (copy, paste, cut, undo, redo, etc) untouched

### Screenshots

_No response_

### NuGet package version

None

### Windows version

_No response_

### Additional context

_No response_

Start by reproducing the RichEditBox behavior with DisabledFormattingAccelerators set to All, including Ctrl+Shift+A and other formatting shortcuts. Trace the property’s handling and verify that all text-format accelerators are disabled while copy, paste, cut, undo, and redo remain available.

Written by the indexing model from the issue text.