Keyboard menu/widget navigation (#628)

* Keyboard menu navigation

* Fix dropdown keyboard navigation

* Fix merge error

* Some code review

* Interactive dropdowns

* Query by data attr not class name

* Add locking behaviour

* Change query selector style

* Change query selector style (again)

* Code review feedback

* Fix highlighted entry regression

* Styling and disabling checkbox tabindex in MenuLists

* Don't redirect space off canvas to backend

* Do not emit update if value same

* Escape closes all floating menus

* Close dropdowns on blur

Co-authored-by: Keavon Chambers <keavon@keavon.com>

frontend/src/components/floating-menus/DialogModal.vue

@@ -90,5 +90,11 @@ export default defineComponent({
 			this.dialog.dismissDialog();
 		},
 	},
+	mounted() {
+		// Focus the first button in the popup
+		const element = this.$el as Element | null;
+		const emphasizedOrFirstButton = (element?.querySelector("[data-emphasized]") as HTMLButtonElement | null) || element?.querySelector("[data-text-button]");
+		emphasizedOrFirstButton?.focus();
+	},
 });
 </script>