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/App.vue

@@ -190,6 +190,23 @@ img {
 	}
 }
 
+.icon-button,
+.text-button,
+.popover-button,
+.checkbox-input label,
+.color-input .swatch .swatch-button,
+.dropdown-input .dropdown-box,
+.font-input .dropdown-box,
+.radio-input button,
+.menu-list,
+.menu-bar-input .entry {
+	&:focus-visible,
+	&.dropdown-box:focus {
+		outline: 1px dashed var(--color-accent);
+		outline-offset: -1px;
+	}
+}
+
 // For placeholder messages (remove eventually)
 .floating-menu {
 	h1,