Accessibility: allow escaping code editors by pressing Esc

See ajaxorg/ace#5114

When the text cursor is in the editor, the user can now press the Esc
key to exit the editor. Pressing the Enter key when the focus ring is
visible around the editor will enter the editor again.

package.json

@@ -5,7 +5,7 @@
     "doc": "docs"
   },
   "dependencies": {
-    "ace-builds": "^1.4.12",
+    "ace-builds": "^1.17.0",
     "big-integer": "^1.6.25",
     "bootstrap": "^3.4.1",
     "bootswatch": "^3.3.7",

src/v1/app.layout.ts

@@ -60,6 +60,7 @@ export class LayoutManager<T> {
             editor.getSession().setMode(`ace/mode/${lang}`);
             if (lang === "yaml")
                 editor.setOption("tabSize", 2);
+            editor.setOption("enableKeyboardAccessibility", true);
             editor.$blockScrolling = Infinity; // TODO: remove this line after they fix ACE not to throw warning to the console
             editor.setReadOnly(isReadOnly);
             if (callback)