Use mastercopy-proxy pattern for all factory contracts

[auryn-macmillan]

This is a duplicate of clrfund/monorepo#359 that was just created over in the monorepo, but it is relevant here as well since the deployer will add at least one additional factory contract to the stack.

TL;DR - we should use a mastercopy-proxy pattern wherever possible.

This is also relevant to #11, #38, #45, and #61.