Add qmlcachegenplus to Qt 6.2 packaging configurations

Information for the packaging configurations:

Component Name: QML Script Compiler
Description: A tool to compile your QML script expressions and functions to C++ ahead of time.
Supported targets: Linux, macOS, Windows for now (others may work, too, but I fear build system issues)
Dependencies to other modules: qtdeclarative. Ignore the optional qtquicktimeline and qtquickcontrols2 dependencies listed in dependencies.yaml when packaging. They're only for the autotests
Technology Preview or Fully Supported: Tech Preview
License: Commercial only
 
Note: qmlcachegenplus is a new git repository requiring possible export tool change.