Added this button in the /u/ user/embed view, so that admins can easily force a re-check from Blender ID without requiring the user themselves to perform any actions.
Instead of performing a call to the Blender Store, call to Blender ID to
get the user's subscription status.
Currently this is performed as a second HTTP call after logging in; in the
future we may want to include the roles in the login response from Blender
ID, so that we can do this in one call instead of two.
Before this, authentication tokens were kept in the database, even when
someone logged out. This is unwanted behaviour, as logging in will create
yet another token anyway there is no reason to keep the token around.