Factorize the different search into one widget

Multiple widgets were implementing their one search and with methods
re-implement in each class. This is obviously difficult to maintain so all
those search were factorize in this widget.
The pqSeachDialog offers 2 main features:
 - If the user presses Esc, the search text is automatically cleared.
 - The advanced button can either: not be displayed, displayed normally
 or displayed and saved/restored as a setting

Consequently replaced the searches in the appropriate widgets by the new
pqSearchBox.

Change-Id: I3e1560634566d6d207c2b1e86877df0b0261d38f
Testing for the pqSearchBox

Add a very basic test for the search box to make sure the basic interaction
are here (Esc key and advanced button clickable).
Fix all the QtTesting test that were influence by the factorization of the
search to pqSearchBox.

Change-Id: Ifc384e8bb3740ee2118585ee119265234c1bec9a