Change demoid to String and now use uuidV7 for it. Also add timestamps of demo uploads

migrations/2024-09-07-151517_demos/up.sql

@@ -1,5 +1,7 @@
 -- Your SQL goes here
 CREATE TABLE IF NOT EXISTS demos (
   steam_id TEXT NOT NULL,
-  demo_id bigint NOT NULL PRIMARY KEY
-)
+  demo_id TEXT NOT NULL,
+  uploaded_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (steam_id, demo_id)
+);