A11y: move focus to right panel when opened (#30553)

* fix: move focus to right panel when opened

* test: update snapshot

* test(e2e): update screenshot

test/unit-tests/components/views/elements/__snapshots__/AppTile-test.tsx.snap

@@ -3,9 +3,11 @@
 exports[`AppTile destroys non-persisted right panel widget on room change 1`] = `
 <DocumentFragment>
   <aside
+    aria-label="Right panel"
     class="mx_RightPanel"
     data-testid="right-panel"
     id="mx_RightPanel"
+    tabindex="-1"
   >
     <div
       class="mx_BaseCard mx_WidgetCard"