Zodbrestore is long-coming counterpart to zodbdump.
Implementation is internally based on reworked zodbcommit.

For FileStorage restored database is verified via test to be bit-to-bit
identical to the original.

For NEO it won't be exactly the case, as NEO does not implement
IStorageRestoreable: there is only tpc_begin(tid=...) but no restore().

/helped-by @jerome
/reviewed-on nexedi/zodbtools!19