Add terminal::Toggle (#37585)

Co-Authored-By: Brandan <b5@n0.computer>

Release Notes:

- Added a new action `terminal::Toggle` that is by default bound to
'ctrl-\`'. This copies the default behaviour from VSCode and Jetbrains
where the terminal opens and closes correctly. If you'd like the old
behaviour you can rebind 'ctrl-\`' to `terminal::ToggleFocus`

Co-authored-by: Brandan <b5@n0.computer>

assets/keymaps/default-linux.json

@@ -583,7 +583,7 @@
       "ctrl-n": "workspace::NewFile",
       "shift-new": "workspace::NewWindow",
       "ctrl-shift-n": "workspace::NewWindow",
-      "ctrl-`": "terminal_panel::ToggleFocus",
+      "ctrl-`": "terminal_panel::Toggle",
       "f10": ["app_menu::OpenApplicationMenu", "Zed"],
       "alt-1": ["workspace::ActivatePane", 0],
       "alt-2": ["workspace::ActivatePane", 1],