Suggestion Window Fixes

[thecoolwinter]

Description

Generally improves a few UX bugs with the suggestion window. Specifically the window would flash often even if the controller did not re-request new items, and would sometimes move the window when it shouldn't have. Also adjusts the window's x position to align the completion labels with the text.

• Centralizes suggestion presentation logic into a single class.
• Moves the trigger character logic out of a filter and into a textview delegate-like method that checks if the last typed character was a trigger character.
  • Ensures the textview and cursor positions are up-to-date when the notification is sent.
• Helps remove duplicate cursor update notifications sent to the suggestion controller by checking if an update is a duplicate in the centralized logic controller.
• Adjusts the suggestion window's x position to align the text in the completion labels with the text being typed.

Also includes a few changes fixing some build warnings.

Related Issues

• Autocomplete Feature #282

Checklist

• I read and understood the contributing guide as well as the code of conduct
• The issues this PR addresses are related to each other
• My changes generate no new warnings
• My code builds and runs on my machine
• My changes are all related to the related issue above
• I documented my code

Screenshots

Screen.Recording.2025-08-25.at.12.32.40.PM.mov