Add support for resizing panes using vim motions (#21038)

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

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/vim/src/replace.rs

@@ -22,7 +22,7 @@ pub fn register(editor: &mut Editor, cx: &mut ViewContext<Vim>) {
         if vim.mode != Mode::Replace {
             return;
         }
-        let count = vim.take_count(cx);
+        let count = Vim::take_count(cx);
         vim.undo_replace(count, cx)
     });
 }