Reactions of deleted message still persist in database

How to use GitHub

• Please use the 👍 reaction to show that you are affected by the same issue.
• Please don't comment if you have no relevant information to add. It's just extra noise for everyone subscribed to this issue.
• Subscribe to receive notifications on status change and new comments.

Steps to reproduce

1. Post a message
2. Add a reaction to it
3. Delete a message

Expected behaviour

Server response should be:

{
  "id": 122,
  "message": "Message deleted by you",
  "messageType": "comment_deleted",
  "reactions": {},
},
{
  "id": 123,
  "message": "Reaction deleted by author",
  "parent": {
    "id": 122,
  }
},
{
  "id": 124,
  "message": "You deleted a message",
  "systemMessage": "message_deleted",
  "parent": {
    "id": 122,
  }
},

Actual behaviour

{
  "id": 122,
  "message": "Message deleted by you",
  "messageType": "comment_deleted",
  "reactions": {},
  "reactionsSelf": [
    "\ud83d\udc4d"
  ]
},
{
  "id": 123,
  "message": "\ud83d\udc4d",
  "systemMessage": "reaction",
  "parent": {
    "id": 122,
  }
},
{
  "id": 124,
  "message": "You deleted a message",
  "systemMessage": "message_deleted",
  "parent": {
    "id": 122,
  }
},

No file or test is named in the issue. First reproduce the post, react, and delete sequence, then trace the server handling behind the returned message and reaction records. Done means deleted messages return no persisted reactions or reaction events, matching the expected JSON.