core, ethdb, tests, trie: introduce database snapshot (#24486)

core/rawdb/table.go

@@ -177,6 +177,13 @@ func (t *table) NewBatchWithSize(size int) ethdb.Batch {
 	return &tableBatch{t.db.NewBatchWithSize(size), t.prefix}
 }
 
+// NewSnapshot creates a database snapshot based on the current state.
+// The created snapshot will not be affected by all following mutations
+// happened on the database.
+func (t *table) NewSnapshot() (ethdb.Snapshot, error) {
+	return t.db.NewSnapshot()
+}
+
 // tableBatch is a wrapper around a database batch that prefixes each key access
 // with a pre-configured string.
 type tableBatch struct {