Add ESC btn to toolbar to quickly exit formatting (#1283)

* Add ESC btn to toolbar to quickly exit formatting

* add horizontal scroll to toolbar item

* make editor toolbar usable in touch device

* fix editor hotkeys not working in window

* remove unused import

src/app/utils/key-symbol.ts

@@ -3,4 +3,7 @@ export enum KeySymbol {
   Shift = '⇧',
   Option = '⌥',
   Control = '⌃',
+  Hyper = '✦',
+  Super = '❖',
+  Escape = '⎋',
 }