Add option to view subscribed users on specific category

[sshcli]

Expected behavior

1. As admin or moderator, You should be able to know what users are subscribed to a specific category.
2. As admin or moderator, you should have the option to receive a notification email every time a user subscribe or unsubscribe from a category.

Actual result
There is no way to know what users are subscribed to a specific category.

System information (please complete the following information)
Joomla version: 3.9.11 and 4.0.0-alpha11-dev
Kunena version: 5.1.14 and 6.0.0-ALPHA4-DEV
Php version: 7.3.8
Database version: MySQL 5.7.27 and MariaDB 10.3.17

[github-actions]

This issue is stale because it has been open 30 days with no activity.

[xillibit]

1. As admin or moderator, You should be able to know what users are subscribed to a specific category.

Where do-you want to see that ? In a tab in user profile in frontend ?

[sshcli]

Where do-you want to see that ? In a tab in user profile in frontend ?

Where it is easier for you. Choose the simplest way.