feat: implement media listing with sorting and filtering options

libertas_core/src/config.rs

@@ -21,4 +21,5 @@ pub struct Config {
     pub broker_url: String,
     pub max_upload_size_mb: Option<u32>,
     pub default_storage_quota_gb: Option<u64>,
+    pub allowed_sort_columns: Option<Vec<String>>,
 }