Fix legacy custom searches to not use hacky method to access protected property on...

Fix legacy custom searches to not use hacky method to access protected property on core class

This avoids passing the form object to a function simply to extract the
links value & instead only calls the form object is it actually implements
the links function - which they basically don't...

This still works - ie I checked the actions are still available in custom searches
but respects the principle that protected variables are not public