CMake: Suggest installation of package for missing Qt 6 component

[cmake] CMake Error at CMakeLists.txt:16 (find_package):
[cmake]   Found package configuration file:
[cmake] 
[cmake]     C:/Qt/6.9.0/msvc2022_64/lib/cmake/Qt6/Qt6Config.cmake
[cmake] 
[cmake]   but it set Qt6_FOUND to FALSE so package "Qt6" is considered to be NOT
[cmake]   FOUND.  Reason given by package:
[cmake] 
[cmake]   Failed to find required Qt component "WebEngineWidgets".
[cmake] 
[cmake]   Expected Config file at
[cmake]   "C:/Qt/6.9.0/msvc2022_64/lib/cmake/Qt6WebEngineWidgets/Qt6WebEngineWidgetsConfig.cmake"
[cmake]   does NOT exist