[ENG-7858] Return number of contacts messages of institutional admins

[ihorsokhanexoft]

Purpose

Admins should be able to see number of messages that each admin sent to the same user

Changes

Added contact property, added a test and fixed existing ones
Contacts are ordered alphabetically
Additional scope: this property was added in export files as well

Ticket

https://openscience.atlassian.net/jira/software/c/projects/ENG/boards/145

[brianjgeiger]

So what I don't like about this solution is that it's going to run that query, with the annotation, on every user on the page when it loads the page. This is going to create additional unnecessary stress on the database, which is what I was trying to avoid.

On the plus side, it does allow us to implement the feature in the way that Product originally wanted, which was to display the count for all users at the start rather than waiting until they hovered over the contact balloon.

We'll go with this, unless we find that the page slowdown is noticeable. Fortunately, these pages don't get used that often all things considered, so we shouldn't be taking down the OSF with it. But if we were making an endpoint that had publicly-accessible data, this would not be the way to do it.