Start to implement the VideoService list_root_folder method.

backend/domain/src/video/model/library_item.rs

@@ -0,0 +1,18 @@
+use uuid::Uuid;
+
+pub enum LibraryItemType {
+    VIDEO,
+    FOLDER
+}
+
+pub struct LibraryItem {
+    pub id: Uuid,
+    pub name: String,
+    pub r#type: LibraryItemType,
+}
+
+pub struct ReadLibraryItem {
+    pub id: Option<Uuid>,
+    pub name: String,
+    pub r#type: LibraryItemType,
+}