Issue notifications preference out of sync after adding reaction

Summary

Adding a reaction to an issue prevents the Notifications toggle in the sidebar from responding correctly to user interaction.

Steps to reproduce

1. Navigate to an issue that you have not interacted with previously
2. Add a 👍 reaction to the issue (thus subscribing you to notifications for that issue)
3. Click the Notifications slider, which results in a UI indication that notifications have been turned on
4. Click the Notifications slider, which results in a UI indication that notifications have been turned off
5. Refresh the page

N.B. This may also be reproducible with other actions that automatically cause the user to enable notifications on an issue.

Example Project

hazelanalytics/hazel

What is the current bug behavior?

The Notifications slider is set to on, which is the opposite of your last interaction.

What is the expected correct behavior?

The Notifications slider should have the same state as it did prior to refreshing the page, correctly reflecting your last interaction.

Furthermore, the Notifications slider should switch to on when a user takes any action that subscribes to notifications as a side effect, so the UI is not initially out of sync with truth.

Output of checks

This bug happens on GitLab.com