This removes CSS selectors associated with the Page tools
feature flag, i.e. `vector-feature-page-tools-disabled` as
well as `vector-feature-page-tools-enabled` by removing
the 'disabled' styles and integrating the 'enabled' styles
into the default page tools code.
Bug: T332090
Change-Id: I382e12ca7ce741a3071582ffa84da03c2ba9e343