feat(drivers): new driver UrlTree (close #3268 in #3933)

* feat(drivers): new driver `urls` (close #3268)

* chore: rename

* support customize basic info or get from url

* dfs tree to calculate folder size

* go mod tidy

* add help message

drivers/url_tree/urls_test.go

@@ -0,0 +1,47 @@
+package url_tree_test
+
+import (
+	"testing"
+
+	"github.com/alist-org/alist/v3/drivers/url_tree"
+)
+
+func testTree() (*url_tree.Node, error) {
+	text := `folder1:
+  name1:url1
+  url2
+  folder2:
+    url3
+    url4
+  url5
+folder3:
+  url6
+  url7
+url8`
+	return url_tree.BuildTree(text, false)
+}
+
+func TestBuildTree(t *testing.T) {
+	node, err := testTree()
+	if err != nil {
+		t.Errorf("failed to build tree: %+v", err)
+	} else {
+		t.Logf("tree: %+v", node)
+	}
+}
+
+func TestGetNode(t *testing.T) {
+	root, err := testTree()
+	if err != nil {
+		t.Errorf("failed to build tree: %+v", err)
+		return
+	}
+	node := url_tree.GetNodeFromRootByPath(root, "/")
+	if node != root {
+		t.Errorf("got wrong node: %+v", node)
+	}
+	url3 := url_tree.GetNodeFromRootByPath(root, "/folder1/folder2/url3")
+	if url3 != root.Children[0].Children[2].Children[0] {
+		t.Errorf("got wrong node: %+v", url3)
+	}
+}