fix: DisplayLayout and FlexibleLayout toolbar actions only apply to selected layout (#7184)

* refactor: convert to ES6 function

* fix: include `keyString` in event name

- This negates the need for complicated logic in determining which objectView the action was intended for

* fix: handle the case of currentView being null

* fix: add keyString to flexibleLayout toolbar events

* fix: properly unregister listeners

* fix: remove unused imports

* fix: revert parameter reorder

* refactor: replace usage of `arguments` with `...args`

* fix: add a11y to display layout + toolbar

* test: add first cut of layout toolbar suite

* test: cleanup a bit and add Image test

* test: add stubs

* fix: remove unused variable

* refactor(DisplayLayoutToolbar): convert to ES6 class

* test: generate localStorage data for display layout tests

* fix: clarify "Add" button label

* test: cleanup and don't parameterize tests

* test: fix path for recycled_local_storage.json

* fix: path to local storage file

* docs: add documentation for
utilizing localStorage in e2e

* fix: path to recycled_local_storage.json

* docs: add note hyperlink

src/plugins/flexibleLayout/flexibleLayoutViewProvider.js

@@ -81,10 +81,9 @@ export default class FlexibleLayoutViewProvider {
           type: 'flexible-layout'
         };
       },
-      contextAction() {
-        const action = arguments[0];
-        if (component && component.$refs.flexibleLayout[action]) {
-          component.$refs.flexibleLayout[action](...Array.from(arguments).splice(1));
+      contextAction(action, ...args) {
+        if (component?.$refs?.flexibleLayout?.[action]) {
+          component.$refs.flexibleLayout[action](...args);
         }
       },
       onEditModeChange(isEditing) {