MCRichDigitsToRawBufferAlg: Use by default 64 bit stream format in dd4hep builds
Using the realistic emulation has little practical advantage to the simpler streaming format, which we have always used (the 32 bit version) in DetDesc builds.
Currently the realistic emulation has issues due to the simulation Cond DB branches used with dd4hep do not have the correct Tel40 link conditions in place. This should be addressed as well, but this MR by passes this by switching to the 64 bit streaming version in dd4hep builds.
In addition, this format will be needed in any future Upgrade 2 productions as it is the only format that supports time information at this point. So making this the default in dd4hep builds makes sense at this time.