Add basic recursive tag searching support based on the search path

src/data/mod.rs

@@ -105,6 +105,7 @@ pub struct FilesRequest {
     pub path: String,
     pub tag_ids: Option<String>, // comma separated numbers
     pub tag_filter_mode: Option<FilterMode>,
+    pub recursive: Option<bool>,
 }
 
 #[derive(Copy, Clone, Deserialize, PartialEq)]