Add select word hotkey

Use case or problem

Place the cursor anywhere within the word, type the hotkey, it can auto select the whole word:
GIF 2023-9-14 15-00-48

Proposed solution

Now we can only use mouse or combined key (Ctrl + left/right) to select words.

Double click won’t work for the following note, if we want to select test.py then wrap it in `, which might is a common use case while editing:

Let's open test.py.