Geant4AssemblyVolume: use the same copy ID for the Geant4 Volume as was set in DD4hep geometry construction

    is now set to [-pi,pi] instead of [0,2pi] if phi IDdescriptor field is signed.

the target is now(?) prefixed with Geant4:: otherwise we get a linking error

It doesn't matter because we don't care about the result

Add implementation for signal handling. Use generic signal handler in DDG4 for controlled shutdown on CTRL-C. Add test DDG4_SIGINT_handler in examples/DDG4

Add implementation for signal handling. Use generic signal handler in DDG4 for controlled shutdown on CTRL-C. Add test DDG4_SIGINT_handler in examples/DDG4

ROOT no longer finds nlohmann_json unless we ask for the ROOTEve
component, so we ask for the ROOTEve component if the ROOTEve
component exists.  DDEve and one executable in UtilityApps depend on
this

fixes some tests that can run in this case successfully now

test_import: change error to fehler to avoid triggering test failure because we get a warning from gosam

conditions: use static unsigned long long int because ROOTs latest llvm otherwise causes assertion in debug mode about not being able to represent in 64 bit. Not sure if bug in enum parsing???