Fix extremely slow update of Semantic Domain List display

This fixes FWNX-973 "Semantic domain search box is blinking After search
a 'GAILS' then remove some letters" and FWNX-1043 "Typing any letter ...
in the search box in Collect Words-->Semantic Domains view takes
approximately 1 minute 29 Seconds for filtering the text".

Change-Id: I3b503b39e5ebd77d7861f49a0bdf3e174cde5011