WebSearch: better retrieval of record tabs

• When retrieving the tabs for the detaild record pages, use the guess_collection_of_a_record() function that also takes into account the referer. (addresses #2068)

Signed-off-by: Ludmila Marian <ludmila.marian@gmail.com>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>