Add missing references to transaction verification consensus rules

[oxarbitrage]

In https://github.com/ZcashFoundation/zebra/blob/v1.0.0-alpha.14/zebra-consensus/src/transaction.rs#L435 and https://github.com/ZcashFoundation/zebra/blob/v1.0.0-alpha.14/zebra-consensus/src/transaction.rs#L522 we implement some consensus rules that dont have any reference in the spec.

Will be good to add them when we get the time as it is hard to find them.

Also, for the binding verification key validation in sapling and in orchard there is no comment nor reference to their corresponding rules in the spec.

This is a low priority issue that was found during #2441

[oxarbitrage]

This was all fixed when we did #3125