[RBDI-15] Bug fixes in all sigs vc.
[RBDI-15] Bug fixes in all sigs vc.

Made the search bar the table header again to fix weird click/dismiss behavior. Changing the data due to a search cancels selected cell without animation to prevent crash.

PDXostc/rvi_big_data_ios,PDXostc/rvi_big_data_ios,PDXostc/rvi_big_data_ios