[feature]: Private comments

Is there an existing issue for this?

• I have searched the existing issues

Summary

Since guests are able to read issues and comments, it could be great if there could be a flag on a comment to be "team only", so only regular members can read it, but guests cannot.

We've used this a lot on the previous platform that we used. It's a great way to still have some discussions without the client, needs to worry about them.

I'm visualising it as a toggle/boolean that you can set on a individual comment to mark it as "team only".

Why should this be worked on?

It's a great way to still have clients or other people of interest have access to the issues, while still being able to have team privat discussion on a issue.