Improve consistency of arithmetic signatures

[christopherkang]

Similar to this issue, arithmetic methods currently have inconsistent signature types.

E.g., consider the Product and Add methods. While the Add method takes in QUInt registers of a specific size, Product takes in ints describing the size of Product inputs:

add_small = Add(QUInt(bitsize=4))
product = Product(a_bitsize=4, b_bitsize=6)

[mpharrigan]

@NoureldinYosri

[mpharrigan]

Thanks for pointing this out! We used to not have data types so there's some historical baggage where the earlier-written bloqs just take a bitsize. We've generally been porting these as we run into the need to support other datatypes; but it's a worthy goal!