Include room ID in room deletion status response (#18318)

When querying by `delete_id` it's handy to see which room the delete
pertains to.

changelog.d/18318.feature

@@ -0,0 +1 @@
+Include room ID in room deletion status response.

docs/admin_api/rooms.md

@@ -794,6 +794,7 @@ A response body like the following is returned:
     "results": [
         {
             "delete_id": "delete_id1",
+            "room_id": "!roomid:example.com",
             "status": "failed",
             "error": "error message",
             "shutdown_room": {
@@ -804,6 +805,7 @@ A response body like the following is returned:
             }
         }, {
             "delete_id": "delete_id2",
+            "room_id": "!roomid:example.com",
             "status": "purging",
             "shutdown_room": {
                 "kicked_users": [
@@ -842,6 +844,8 @@ A response body like the following is returned:
 ```json
 {
     "status": "purging",
+    "delete_id": "bHkCNQpHqOaFhPtK",
+    "room_id": "!roomid:example.com",
     "shutdown_room": {
         "kicked_users": [
             "@foobar:example.com"
@@ -869,7 +873,8 @@ The following fields are returned in the JSON response body:
 - `results` - An array of objects, each containing information about one task.
   This field is omitted from the result when you query by `delete_id`.
   Task objects contain the following fields:
-  - `delete_id` - The ID for this purge if you query by `room_id`.
+  - `delete_id` - The ID for this purge
+  - `room_id` - The ID of the room being deleted
   - `status` - The status will be one of:
     - `shutting_down` - The process is removing users from the room.
     - `purging` - The process is purging the room and event data from database.

synapse/rest/admin/rooms.py

@@ -150,6 +150,7 @@ class RoomRestV2Servlet(RestServlet):
 def _convert_delete_task_to_response(task: ScheduledTask) -> JsonDict:
     return {
         "delete_id": task.id,
+        "room_id": task.resource_id,
         "status": task.status,
         "shutdown_room": task.result,
     }

tests/rest/admin/test_room.py

@@ -758,6 +758,8 @@ class DeleteRoomV2TestCase(unittest.HomeserverTestCase):
         self.assertEqual(2, len(channel.json_body["results"]))
         self.assertEqual("complete", channel.json_body["results"][0]["status"])
         self.assertEqual("complete", channel.json_body["results"][1]["status"])
+        self.assertEqual(self.room_id, channel.json_body["results"][0]["room_id"])
+        self.assertEqual(self.room_id, channel.json_body["results"][1]["room_id"])
         delete_ids = {delete_id1, delete_id2}
         self.assertTrue(channel.json_body["results"][0]["delete_id"] in delete_ids)
         delete_ids.remove(channel.json_body["results"][0]["delete_id"])
@@ -777,6 +779,7 @@ class DeleteRoomV2TestCase(unittest.HomeserverTestCase):
         self.assertEqual(1, len(channel.json_body["results"]))
         self.assertEqual("complete", channel.json_body["results"][0]["status"])
         self.assertEqual(delete_id2, channel.json_body["results"][0]["delete_id"])
+        self.assertEqual(self.room_id, channel.json_body["results"][0]["room_id"])
 
         # get status after more than clearing time for all tasks
         self.reactor.advance(TaskScheduler.KEEP_TASKS_FOR_MS / 1000 / 2)
@@ -1237,6 +1240,9 @@ class DeleteRoomV2TestCase(unittest.HomeserverTestCase):
         self.assertEqual(
             delete_id, channel_room_id.json_body["results"][0]["delete_id"]
         )
+        self.assertEqual(
+            self.room_id, channel_room_id.json_body["results"][0]["room_id"]
+        )
 
         # get information by delete_id
         channel_delete_id = self.make_request(
@@ -1249,6 +1255,7 @@ class DeleteRoomV2TestCase(unittest.HomeserverTestCase):
             channel_delete_id.code,
             msg=channel_delete_id.json_body,
         )
+        self.assertEqual(self.room_id, channel_delete_id.json_body["room_id"])
 
         # test values that are the same in both responses
         for content in [