We only used them for registered users, but MobileFrontend's
EditorOverlay code can use them for anonymous users as well.
Remove code for looking up block details in wgMinervaUserBlockInfo,
now we only care whether the user is blocked at all to display a
different icon. MobileFrontend looks up the same information via API
already.
Remove unused message 'mobile-frontend-editor-blocked-info-loggedin',
it was only used by non-fancy popups, which were removed in favor of
the new ones in f51cf7db7b.
Bug: T193754
Bug: T198765
Depends-On: I80564c3e6e2d0f4d7eae754f206780fb4054f254
Change-Id: I64be24845b4fee76d6b4a8e481a218f2160fced6