A beamformer should provide a calibration function. Without it an
application using the beamformer must implement its own and is of little
use other than wanting to use predetermined weights. Considering this,
adding the correlation infrastracture (dedicated array data,
`d_cor_matrix` and others) as part of the rtbf context then makes sense.

This also caused a change to the cublas structure to remove the generic
`_A`, `_B`, and `_C` suffix naming to more specific naming for use.
Providing a dedicated pointer-to-pointer interface for the correlation
output data. Removing the need to reuse the `d_arr_C`.

Having the allocations available along side the beamformer is also
looking forward to want to provide real-time adaptive rfi cancellation.
Because, this helps set them up to run together. Otherwise, reusing a
memory region (`d_beamformed`) or the cublas context resources
(`d_arr_A/C`) requires that resources be shared and reconfigured between
the two operations.  Which would work but perhaps too complicated for
what we want to do.