fix(windows): bool return value of KeymanIsTextSelected

[rc-swag]

Fixes: #12649

Note: there was a comment here about adding a new api function. Which we could do but if we did that we would need to update the TIPProcessKey so an new API call. As noted here
If we going to have to make a new version of TIPProcessKey it would probably better to just add a new argument function pointer to TIPProcessKey, which is IsTextSelected function and keep TIPGetContext the same.

User Testing

TEST_DELETE_SELECTED_TEXT

Install the Keyman for Windows build artifact with this PR.
This test must be done with an application using the Text Services Framework (TSF). You cannot use
the Web version of Word. Use WordPad that comes installed with Windows 10 and Windows 11.

Install a Keyman keyboard like EuroLatin

1. Select the EuroLatin Keyboard
2. Open MS Word or WordPad
3. Type mySchool
4. Select School and type backspace

Expected result
my

Some regression tests.

TEST_BACKSPACE_NO_SELECTION

Install a Keyman keyboard like euro_latin

1. Select the EuroLatin Keyboard
2. Open MS Word or WordPad
3. Type mySchool
4. With the cursor still to the right of 'l' type backspace

Expected result
mySchoo

TEST_SELECTION_TYPE_CHAR

1. Select the EuroLatin Keyboard
2. Open MS Word or WordPad
3. Type mySchool
4. Select School and type t

Expected result
myt

[keymanapp-test-bot]

User Test Results

Test specification and instructions

• ⬜ TEST_DELETE_SELECTED_TEXT (OPEN)
• ⬜ TEST_BACKSPACE_NO_SELECTION (OPEN)
• ⬜ TEST_SELECTION_TYPE_CHAR (OPEN)

Results Template

# Test Results

* **TEST_DELETE_SELECTED_TEXT (OPEN):** notes
* **TEST_BACKSPACE_NO_SELECTION (OPEN):** notes
* **TEST_SELECTION_TYPE_CHAR (OPEN):** notes

Test Artifacts

• Windows
  • Keyman for Windows
  • FirstVoices Keyboards for Windows
  • Text Editor (32 bit)
  • Text Editor (64 bit)