vim: keymap tweaks (#2674)

A few small tweaks to fix some of the community issues

Release Notes:

- vim: Fix `escape` in command palette
([#1347](https://github.com/zed-industries/community/issues/1347)).
- vim: Allow `^` as a motion in actions
([#856](https://github.com/zed-industries/community/issues/856)).
- vim: Allow `ctrl-c` to exit visual mode
([#1447](https://github.com/zed-industries/community/issues/1447)).

crates/vim/src/test/vim_test_context.rs

@@ -21,12 +21,14 @@ impl<'a> VimTestContext<'a> {
         cx.update(|cx| {
             search::init(cx);
             crate::init(cx);
+            command_palette::init(cx);
         });
 
         cx.update(|cx| {
             cx.update_global(|store: &mut SettingsStore, cx| {
                 store.update_user_settings::<VimModeSetting>(cx, |s| *s = Some(enabled));
             });
+            settings::KeymapFile::load_asset("keymaps/default.json", cx).unwrap();
             settings::KeymapFile::load_asset("keymaps/vim.json", cx).unwrap();
         });