Renabling PARAVIEW_ENABLE_QT_SUPPORT variable.

This also reenables Lock-Interactive-Render feature which was accidently
disabled during PV modularization.

Change-Id: I7139290e083430be6275ad0808dafb3bd63ac921
Merge topic '0013777-fix-lock-interactive-render' into next

73be2b0 Renabling PARAVIEW_ENABLE_QT_SUPPORT variable.