Message validation

[Herve-be]

Hi,
This is not really an issue but a request :
I'm looking for something similar but at message level instead of subject level.
Explanation
For the proper functioning of a forum each message must be read by at least one moderator or administrator.
Currently in our forum each message is read by all moderators and by all administrators which represents a waste of time.
I'm looking for an extension that would add (only for administrators and moderators) a button to each message;
when you click on the button a is added next to the title of the message meaning that an administrator or a moderator has already validated it and that it is therefore useless to review it again;
should be visible when viewing a list of new or unread messages.

As it looks very close to your "Topic Solved" extension perhaps you know one that makes the job or you can develop a new one ?
Thanks a lot for reading