[Improvement] Batch operations with validation reuse

[adam-alchemy]

(Brought up in old Spec Update 3 discussions and again by Ross in eth-magicians)

• Currently, generalized batched operations are only possible with self-calls through executeBatch. These are clumsy and somewhat inefficient, for two reasons:
  • The ability for self-calls to always be validated is not part of the spec, but has been the behavior of the ownership plugins. This may not always be the case for other ownership plugins.
  • This causes runtime validation to be run once per item in the batch. This is needlessly wasteful, usually the actions within this cal be collectively validated and reused. However, managing this authorization data is tricky, because a naive implementation like multicall would result in the validation function over multicall itself to implicitly be a validation function for everything.

[adamegyed]

Addressed in this PR: erc6900/reference-implementation#78