🕵️ 🐞 Bug Report: Notes showing other users from other sub-sites in a multisite network

### Prerequisites

- [X] I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
- [X] The issue still exists against the latest stable version of Elementor.

### Description

To be honest the notes feature isn't useful in the majority of cases but I have just tried to try it on a client that likes to annotate as they go along but when I tested it with them when you '@' a user it seems to list other users not from that subsite. I don't think this is good at all. Can you fix this so the mentions only show users from the current site only and maybe super users and not from the whole user database of the multisite as other client usernames should be private. The business I work for uses small clusters of sites within a multisite for ease of deployment and maintenance.

Let me know if you have any questions

### Steps to reproduce

On a WordPress multisite environment with a few sub-sites with different users under them enable the notes permission on an editor role user on one of them, navigate to the homepage and start adding a note as that user. Try and do an '@' mention to a user not from that site.