* Add PowerLevelSelector.tsx.
It's extracting the current behavior of the privileged users and muted of `RolesRoomSettingsTab.tsx` into a dedicated component.
It's also adding a new apply button.
* Use `PowerLevelSelector` to render privileged and muted users in `RolesRoomSettingsTab`
* Update existing tests
* Add playwright test
* Fix typo
* Fix typo
