New theme ui in user settings (#12576)

* Add hook to get the theme

* Adapt subsection settings to new ui

* WIP new theme subsection

* Add theme selection

* Fix test types

* Disabled theme selector when system theme is used

* Update compound to `4.4.1`

* Add custom theme support

* Remove old ThemChoicePanel

* Fix QuickThemeSwitcher-test.tsx

* Fix AppearanceUserSettingsTab-test.tsx

* Update i18n

* Fix ThemeChoicePanel-test.tsx

* Update `@vector-im/compound-web`

* Small tweaks

* Fix CSS comments and use compound variable

* Remove custom theme title

* i18n: update

* test: add tests to theme selection

* test: update AppearanceUserSettingsTab-test snapshot

* test: rework custom theme

* playwright: fix audio-player.spec.ts

* playwright: appearance tab

* test: update snapshot

* playright: add custom theme

* i18n: use correct char for ellipsis

* a11y: add missing aria-label to delete button

* dialog: update close button tooltip

* theme: remove local state and handle custom delete

* theme: don't add twice the same custom theme

* test: update snapshot

* playwright: update snapshot

* custom theme: add background to custom theme list

* update compound web

* Use new destructive property on `IconButton` of theme panel

* test: update snapshots

* rename new ui into legacy

* remove wrong constructor doc

* fix theme selector padding

* theme selector: fix key

* test: fix e2e

src/components/views/dialogs/BaseDialog.tsx

@@ -128,7 +128,8 @@ export default class BaseDialog extends React.Component<IProps> {
                     onClick={this.onCancelClick}
                     className="mx_Dialog_cancelButton"
                     aria-label={_t("dialog_close_label")}
-                    title={_t("dialog_close_label")}
+                    title={_t("action|close")}
+                    placement="bottom"
                 />
             );
         }