Allow system admins to see all sent email notifications

[#1]

Description - I feel like this could be a reportable object, but at the very least would like a place to see what email notifications were sent, to who, when, and what triggered it. 

Why is this feature important to you - We get a lot of complaints that Workfront sends too many duplicative emails. It's really difficult to understand exactly which ones different people need without being able to see exactly what notifications they get. The documentation that explains the different types of emails is not sufficient. It's also difficult to know how the proof email notifications and WF email notifications work together. It seems like they don't at all and constantly send duplicative information.

[#2]

I could absolutely get behind this. You can see a log of emails sent for a Proof, and I find that INCREDIBLY helpful when diagnosing any issues. It's what alerted us to emails going to spam - since we could see a log on Workfront's end that the email went out, we knew the issue was on our company's end. Upvoted and hope other do the same.

[#3]

Building on this, an easy way to also see the various alerts configured by user/team/group as well. I've got a very irritated group of users right now because some of them get the alerts they want, but others don't get them. 

Spoiler: After looking up each of their accounts, I'm trying to find a polite way to say 'If you turn the email alerts off....you don't get emails.' but a report-view would make that much more concise to do.