cmd, core, ethdb, node: move chain freezer one folder deeper (#25487)

* cmd, core, ethdb, node: create chain freezer in a sub folder

* core/rawdb: remove unused code

* core, ethdb, node: add AncientDatadir API back

* cmd, core: extend freezer info dump for sub-ancient-store

* core/rawdb: rework freezer inspector

* core/rawdb: address comments from Peter

* core/rawdb: fix build issue

node/node.go

@@ -703,7 +703,7 @@ func (n *Node) OpenDatabase(name string, cache, handles int, namespace string, r
 // also attaching a chain freezer to it that moves ancient chain data from the
 // database to immutable append-only files. If the node is an ephemeral one, a
 // memory database is returned.
-func (n *Node) OpenDatabaseWithFreezer(name string, cache, handles int, freezer, namespace string, readonly bool) (ethdb.Database, error) {
+func (n *Node) OpenDatabaseWithFreezer(name string, cache, handles int, ancient string, namespace string, readonly bool) (ethdb.Database, error) {
 	n.lock.Lock()
 	defer n.lock.Unlock()
 	if n.state == closedState {
@@ -715,14 +715,7 @@ func (n *Node) OpenDatabaseWithFreezer(name string, cache, handles int, freezer,
 	if n.config.DataDir == "" {
 		db = rawdb.NewMemoryDatabase()
 	} else {
-		root := n.ResolvePath(name)
-		switch {
-		case freezer == "":
-			freezer = filepath.Join(root, "ancient")
-		case !filepath.IsAbs(freezer):
-			freezer = n.ResolvePath(freezer)
-		}
-		db, err = rawdb.NewLevelDBDatabaseWithFreezer(root, cache, handles, freezer, namespace, readonly)
+		db, err = rawdb.NewLevelDBDatabaseWithFreezer(n.ResolvePath(name), cache, handles, n.ResolveAncient(name, ancient), namespace, readonly)
 	}
 
 	if err == nil {
@@ -736,6 +729,17 @@ func (n *Node) ResolvePath(x string) string {
 	return n.config.ResolvePath(x)
 }
 
+// ResolveAncient returns the absolute path of the root ancient directory.
+func (n *Node) ResolveAncient(name string, ancient string) string {
+	switch {
+	case ancient == "":
+		ancient = filepath.Join(n.ResolvePath(name), "ancient")
+	case !filepath.IsAbs(ancient):
+		ancient = n.ResolvePath(ancient)
+	}
+	return ancient
+}
+
 // closeTrackingDB wraps the Close method of a database. When the database is closed by the
 // service, the wrapper removes it from the node's database map. This ensures that Node
 // won't auto-close the database if it is closed by the service that opened it.