cmd, core, trie: verkle-capable geth init (#28270)

This change allows the creation of a genesis block for verkle testnets. This makes for a chunk of code that is easier to review and still touches many discussion points.

trie/database.go

@@ -31,6 +31,7 @@ import (
 // Config defines all necessary options for database.
 type Config struct {
 	Preimages bool           // Flag whether the preimage of node key is recorded
+	IsVerkle  bool           // Flag whether the db is holding a verkle tree
 	HashDB    *hashdb.Config // Configs for hash-based scheme
 	PathDB    *pathdb.Config // Configs for experimental path-based scheme
 }
@@ -318,3 +319,8 @@ func (db *Database) SetBufferSize(size int) error {
 	}
 	return pdb.SetBufferSize(size)
 }
+
+// IsVerkle returns the indicator if the database is holding a verkle tree.
+func (db *Database) IsVerkle() bool {
+	return db.config.IsVerkle
+}