bug: paykit can accept a proposal other than the one the user reviewed #1471

Twin: synonymdev/bitkit-ios#922
Refs: #1470

What happened?

Accepting a one-time payment or subscription didn't stay bound to the proposal the user reviewed, so a missing or replaced proposal could be accepted from an outdated review.

Expected behavior

Bitkit accepts only the proposal shown in the review, on Paykit rc74.