Made Athena explicitly look up Qt5 components during configuration.

This is necessary to be able to build packages (like VP1Algs) that
only indirectly depend on Qt5.

Projects/Athena/cmake/PreConfig.cmake.in

+# Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 #
 # Pre-config script to propagate variables to downstream projects
 #
@@ -17,4 +18,5 @@ if( Athena_FIND_QUIETLY )
 endif()
 find_package( Acts ${_quietFlag} COMPONENTS Core )
 find_package( nlohmann_json ${_quietFlag} )
+find_package( Qt5 COMPONENTS Core OpenGL Gui PrintSupport Widgets Sql Network )
 unset( _quietFlag )