[PLT-3377] Open up a shortcuts dialog instead of printing help text (#7064)

* open up a shortcuts dialog instead of printing help text

* Updating UI for keyboard shortcuts modal

* update PR per PLT-7284

* fix typo error

* fix mixed up shortcut keys

* move to client side

* fix shortcuts list, remove unused function and revert server side code for autocompletion

* remove quick team switcher

webapp/utils/constants.jsx

@@ -168,6 +168,7 @@ export const ActionTypes = keyMirror({
     USER_TYPING: null,
 
     TOGGLE_ACCOUNT_SETTINGS_MODAL: null,
+    TOGGLE_SHORTCUTS_MODAL: null,
     TOGGLE_IMPORT_THEME_MODAL: null,
     TOGGLE_INVITE_MEMBER_MODAL: null,
     TOGGLE_LEAVE_TEAM_MODAL: null,