Denied/Removed group joining requests not recorded

When a user requests to join an open group the following is added to the user's notes:
User joined group and needs to be approved
» Jr. Extension Validators

This is fine as it is but there is no note added when the request is denied, i.e. the group leader removes the request. A follow-up note should be added when either the user is approved or denied, something along the lines of:
User added to group
» Jr. Extension Validators

User removed from group
» Jr. Extension Validators

The action would obviously have the correct user ID of the user that took the action.