Made book-sort changes based on screen reader testing

- Removed having sort items in tabbing order since they have no action.
- Updated "show other books" list to add upon single selection since it
  was not clear how these were added (double press) without then seeing
the add button, and even then the add button would be after the scroll
list.

resources/js/components/entity-selector.js

@@ -15,7 +15,6 @@ export class EntitySelector extends Component {
         this.searchInput = this.$refs.search;
         this.loading = this.$refs.loading;
         this.resultsContainer = this.$refs.results;
-        this.addButton = this.$refs.add;
 
         this.search = '';
         this.lastClick = 0;
@@ -43,15 +42,6 @@ export class EntitySelector extends Component {
             if (event.keyCode === 13) event.preventDefault();
         });
 
-        if (this.addButton) {
-            this.addButton.addEventListener('click', event => {
-                if (this.selectedItemData) {
-                    this.confirmSelection(this.selectedItemData);
-                    this.unselectAll();
-                }
-            });
-        }
-
         // Keyboard navigation
         onChildEvent(this.$el, '[data-entity-type]', 'keydown', (e, el) => {
             if (e.ctrlKey && e.code === 'Enter') {