Iterate landmarks around the app in order to improve a11y (#12064)

* Iterate landmarks around the app in order to improve a11y

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Add missing aria-label

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Update snapshots

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* i18n

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Fix tests

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Iterate

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Update screenshots which have changed a fraction due to default heading margins being different in different landmarks

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

---------

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/structures/ThreadPanel.tsx

@@ -180,11 +180,11 @@ const EmptyThread: React.FC<EmptyThreadIProps> = ({ hasThreads, filterOption, sh
     }
 
     return (
-        <aside className="mx_ThreadPanel_empty">
+        <div className="mx_ThreadPanel_empty">
             <div className="mx_ThreadPanel_largeIcon" />
             <h2>{_t("threads|empty_heading")}</h2>
             {body}
-        </aside>
+        </div>
     );
 };