bug(mac): Key processing with text selection problems

### Describe the bug

The Text Selection and Key Processing spc test cases with legacy apps show some limitations.

Please have a look here for the [test cases](https://github.com/keymanapp/keyman/issues/9073) and the [Google doc](https://docs.google.com/spreadsheets/d/1NDO82y77C45pw_ZcMPcD36NZ4VUy9hQcuByieyeJVtM/edit#gid=0) for the test results.

See also: [Compatibility Testing A19S24](https://docs.google.com/document/d/1oWsE8V2or8mBqqJMju3em5D_x7l0V0N8Ry1Iq4x77IY/edit?tab=t.0)

Keyman 17.0.218
macOS 14.1.1
Google Chrome 119.0.6045.199

### Reproduce the bug

Failed tests:
---------------------------------------------------------

~1. (T02) ^⁞X the quick brown fox⁞ in doc. Typing BKSP, then Shift+A.
Expected result: Â⁞
Actual result:^A⁞
2. (T04) ^⁞X⁞ in doc. Typing Shift+A.
Expected result: Â⁞
Actual result:^A
3. (T05) ^⁞X the quick brown fox⁞ in doc. Typing Shift+A.
Expected result: Â⁞
Actual result:^A~
4. (T07) ^⁞X⁞ in doc. Typing BKSP, BKSP.
Expected result: foo⁞
Actual result: Blank
5. (T09) a⁞bc de⁞ in doc with selection starting at b. Typing BKSP.
Expected result: a⁞
Actual result: ab
6. (T15) Type X, A followed by [K_BKQUOTE] and B. Select B (Xa⁞b⁞).
Press BKSP twice.
Expected result: X⁞
Actual result: Xa
7. (T16) Type X, A followed by [K_BKQUOTE] and B. Select B (Xa⁞b⁞).
Press BKSP then O.
Expected result: Xao⁞
Actual result: Xa`o
8. T17) Type 1 followed by TAB key, then type 1.
Expected result: ፩
Actual result: After pressing the TAB key move the cursor to the bottom of the page.

### Expected behavior

_No response_

### Related issues

#10012

### Keyman apps

- [ ] Keyman for Android
- [ ] Keyman for iPhone and iPad
- [ ] Keyman for Linux
- [X] Keyman for macOS
- [ ] Keyman for Windows
- [ ] Keyman Developer
- [ ] KeymanWeb
- [ ] Other - give details at bottom of form

### Keyman version

17.0.218-alpha

### Operating system

macOS 14.1.1 Sonoma

### Device

_No response_

### Target application

_No response_

### Browser

Chrome

### Keyboard name

_No response_

### Keyboard version

_No response_

### Language name

_No response_

### Additional context

_No response_

Edit 2025-04-24: updated T02, T04, T05 because selecting the text causes us to loose the context in a non-compliant app, so the result we got is correct.