Added "Favorites" quickfilter button

Since quickfilter doesn't work when only showing favorites, it made
sense to have an easy way to do that.

I shrunk the current breed filter buttons slightly to fit an extra
button at the end.  It uses the "Star" favorites icon and reads your
current "favorites filter" state when loaded.
Read filtering state on load

Since filtering state is saved between reloads, it makes sense to set
the filters status according to the current filters state.

This fix reads the state of the filter at load time and sets the buttons
accordingly.  If all pet types are currently not filtered (i.e. all pet
types are showing) we update the ui to not show any filter.