Add support for resizing panes using vim motions

[AidanV]

Closes #8628

Release Notes:

• Added support for resizing the current pane using vim keybinds with the intention to follow the functionality of vim
  • "ctrl-w +" to make a pane taller
  • "ctrl-w -" to make the pane shorter
  • "ctrl-w >" to make a pane wider
  • "ctrl-w <" to make the pane narrower
• Changed vim pre_count and post_count to globals to allow for other crates to use the vim count. In this case, it allows for resizing by more than one unit. For example, "10 ctrl-w -" will decrease the height of the pane 10 times more than "ctrl-w -"
• This pr does not add keybinds for making all panes in an axis equal size and does not add support for resizing docks. This is mentioned because these could be implied by the original issue