Add missing Qt component to silence CMake warnings

The project cafProjectDataModel_UnitTests was triggering multiple
CMake warnings saying that the Widget component was missing when trying
to collect dependencies.

Fwk/AppFwk/cafProjectDataModel/cafProjectDataModel_UnitTests/CMakeLists.txt

@@ -7,7 +7,7 @@ if(CEE_USE_QT6)
   find_package(
     Qt6
     COMPONENTS
-    REQUIRED Core
+    REQUIRED Core Widgets
   )
   qt_standard_project_setup()
 else()