Closes #28699

Fixes two cases in the `editor::SelectLargerSyntaxNode` action:
1. When cursor is at the end of a word, it now selects that word first
instead of selecting the whole line.
2. When cursor is at the end of a line, it now selects that line first
instead of selecting the whole code block.

Before and After:


https://github.com/user-attachments/assets/233b891e-15f1-4f10-a51f-75693323c2bd

Release Notes:

- Fixed `editor::SelectLargerSyntaxNode` to properly select nodes when
the cursor is positioned at the end of words or lines.