Add ZoomToSelection feature and Selection Manager
ZoomToSelection feature is introduced in this MR. For model builder it will zoom to selected entityRefs, for other applications it would just zoom to selected data. Selection manager lives in pqCMBCommonMainWindowCore which take's care of selection between SMTK and CMB. Check SMTK MR ff2876bf28db03a867d6f370d1334e6a74d360f7 for detail.
Merge it when SMTK!379 is merged in.