refactor: split migration of task status updated

Author: MarcosNicolau

aggregation_mode/db/migrations/001_init.sql

@@ -9,8 +9,7 @@ CREATE TABLE tasks (
     merkle_path BYTEA,
     status task_status DEFAULT 'pending',
     nonce BIGINT NOT NULL,
-    inserted_at TIMESTAMPTZ NOT NULL DEFAULT now(),
-    status_updated_at TIMESTAMPTZ DEFAULT now()
+    inserted_at TIMESTAMPTZ NOT NULL DEFAULT now()
 );
 
 CREATE TABLE payment_events (

aggregation_mode/db/migrations/002_task_status_updated_at.sql

@@ -0,0 +1 @@
+ALTER TABLE tasks add COLUMN status_updated_at TIMESTAMPTZ DEFAULT now();