Change finalize to only squash commits

[herr-seppia]

Summary

Currently, if the state root returned by the finalize operation mismatch, it's impossible to revert

Possible solution design or implementation

Since accept and finalize are the same operations except for the squashing strategy, we should change the node in order to always call "accept" and, if the state hash match, call finalize to squash previous commits (if the block is finalizable).
This requires that finalize must not process transactions, but just squash commits between from and to (at the beginning, we can omit to explicitly pass those variables, since they are known by rusk)

Additional context

In addition, it would be useful to change the Accept method in order to receive the expected state root. If that is not matching the effective result, the vm should not commit

Persist block should be done only after ensure that state_root returned by accept/finalize is the same of the block header
See also #924

Originally posted by @herr-seppia in #902 (comment)

[goshawk-3]

As the ultimate resolution, we concluded to implement a consistency_check in both the accept and finalize calls. This validation enables a caller to ensure the commitment of a VM state change only when a valid state_root is returned.