Double DAQ_DCU_SIZE, and eliminate time 2 operations on it throughout the code.

Double DAQ_DCU_SIZE. Throughout the code (but not everywhere), DAQ_DCU_SIZE * 2 was being used. However, it should universally be doubled. Putting the change in the constant where it belongs facilitates future increases in DAQ block sizes.

This change affects many areas: the models, daq, standalone_edc, local_dc, awgtpman, pubsub. However, only in those cases where there was not a '* 2' will there be a substantive change.

I have rebuilt models and awgtpman, then successfully run excitations with older local_dc, pubsub and daqd. I have not tested the changes in local_dc, pbusub, or daqd.