FileSearch: Remove duplicated code between regexp and non-regexp search
FileSearch: Remove duplicated code between regexp and non-regexp search

Only the way individual files are searched is different, so the rest of
the code is now shared.

Change-Id: Ia550de1b5d381c5f7c26c3f3e7a943fea7d0efa9
Reviewed-by: David Schulz <f07954e8cc0c222cd136162588d217f330598215@theqtcompany.com>

xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator