Improve the usability of the cursor movement in the commit window

**Is your feature request related to a problem? Please describe.**
In the commit window only char by char movement with the left and right arrow is possible.
In input fields (or most text editors) if you press ctrl (option on mac) and the left/right arrow key the cursor moves word by word not character by character.

**Describe the solution you'd like**
Move word by word, if ctrl (option on mac) is pressed with the arrow keys

**Describe alternatives you've considered**
None

**Additional context**
To make it perfect support also selection with the movent keys.
If shift is pressed it will be selected (shift+arrow selects the character / shift+ctrl+arrow selects the whole word, moving in reverse un-selects)
I know that implementing selection correctly is quite complicated and I don't know how lazygit implemented the TUI (custom UI or a library), and therefore I don't know if a selection is possible at all