feat(pruning): Record L1 batch root hash in pruning logs (#3266)

## What ❔

Records root hashes of the last hard-pruned L1 batch in pruning logs.

## Why ❔

This allows to check tree integrity after recovery after pruning.

## Checklist

- [x] PR title corresponds to the body of PR (we generate changelog
entries from PRs).
- [x] Tests for the changes have been added / updated.
- [x] Documentation comments have been added / updated.
- [x] Code has been formatted via `zkstack dev fmt` and `zkstack dev
lint`.

core/lib/dal/migrations/20241112120944_add_batch_root_hash_to_pruning_logs.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE pruning_log
+    DROP COLUMN pruned_l1_batch_root_hash;

core/lib/dal/migrations/20241112120944_add_batch_root_hash_to_pruning_logs.up.sql

@@ -0,0 +1,3 @@
+-- nullable for backward compatibility
+ALTER TABLE pruning_log
+    ADD COLUMN pruned_l1_batch_root_hash BYTEA DEFAULT NULL;

core/lib/dal/src/consensus_dal/mod.rs

@@ -301,10 +301,10 @@ impl ConsensusDal<'_, '_> {
             .get_pruning_info()
             .await
             .context("get_pruning_info()")?;
-        Ok(match info.last_soft_pruned_l2_block {
+        Ok(match info.last_soft_pruned {
             // It is guaranteed that pruning info values are set for storage recovered from
             // snapshot, even if pruning was not enabled.
-            Some(last_pruned) => validator::BlockNumber(last_pruned.0.into()) + 1,
+            Some(last_pruned) => validator::BlockNumber(last_pruned.l2_block.0.into()) + 1,
             // No snapshot and no pruning:
             None => validator::BlockNumber(0),
         })