Rollup node: snapshot import

Context

This MR allows the rollup node to import snapshots produced with the command snapshot export using the command snapshot import _. Rollup nodes which are not initialized will accept any snapshot, but the other ones will only accept snapshots for the corresponding history mode and rollup address which are later on the chain than their head.

Depends on !10704 (merged).

Manually testing the MR

dune exec tezt/tests/main.exe -- -f sc_rollup.ml snapshot