Move the active tab in user settings to the dialog title (#12481)

* Convert tabbedview to functional component

The 'Tab' is still a class, so now it's a functional component that
has a supporting class, which is maybe a bit... jarring, but I think
is actually perfectly logical.

* put comment back

* Fix bad tab ID behaviour

* Make TabbedView a controlled component

This does mean the logic of keeping what tab is active is now in each
container component, but for a functional component, this is a single
line. It makes TabbedView simpler and the container components always
know exactly what tab is being displayed rather than having to effectively
keep the state separately themselves if they wanted it.

Based on https://github.com/matrix-org/matrix-react-sdk/pull/12478

* Move the active tab in user settings to the dialog title

Separated by a colon, as per the new design.

* Update snapshots

* Update a playwright test

* Fix more tests / snapshots

* Attempt to test all the cases of titleForTabID

* More tests

playwright/e2e/settings/appearance-user-settings-tab.spec.ts

@@ -25,8 +25,6 @@ test.describe("Appearance user settings tab", () => {
     test("should be rendered properly", async ({ page, user, app }) => {
         const tab = await app.settings.openUserSettings("Appearance");
 
-        await expect(tab.getByRole("heading", { name: "Customise your appearance" })).toBeVisible();
-
         // Click "Show advanced" link button
         await tab.getByRole("button", { name: "Show advanced" }).click();