Natively typed numpy arrays

[mkolopanis]

Many of the blocks.py interactions with FPGAs re-cast arrays back to default numpy (float64) or overcast u16s to int32s.
On the software call 02 May 2022, we discussed having these arrays retain their native types instead of being recast in python.
This will affect conversioning in HERA-Team/hera_corr_cm#60 but we will not need a conv + cast architecture there anymore.