Multiple equal reactions from user are displayed multiple times

[krille-chan]

Bug Description

When multiple m.reaction events are sent from a user with the same key and rel_type from the same user, it causes their reactions to add up rather than just being displayed once.

Steps to Reproduce

1. Send a message
2. Get the event id
3. Use element devtools to send this event multiple times of type m.reaction:

"m.relates_to": {
  "event_id": "${event_id}",
  "key": "👍",
  "rel_type": "m.annotation"
}

4. See issue

Expected Behavior

Only one reaction of a certain emoji should be displayed for a single user.

Multiple identical annotations (i.e., with the same event type and annotation key) from the same user (i.e., events with the same sender) should be treated as a single annotation.

https://spec.matrix.org/v1.10/client-server-api/#annotations-client-behaviour

App Version

1.18.0

Additional Platform Information

Redmi Note 9 Pro, Android 12

Additional Context

Multiple reactions in the real world can be caused by buggy clients, multiple clients reacting at the same time, lag, etc.