Adds Total Checkins to Admin Event View + Updates Scanner unauthorized response

[christianhelp]

Why

This PR is comprised of two main issues:

1. From Rowdyhacks, we noticed that there was no easy way to see the total number of scans for an individual event in the UI without querying the db directly.
2. While testing this feature, it was noticed that there was an issue with the scanner where I did not have the proper permissions, yet I was still shown a success state for the UI when trying to scan a user in

What

1. Added a new function that gets events with the total amount of scans
2. Added extra error handling for users not being authorized. In the future, users unable to scan others in should simply not have this option to go to the scanners and the page should reject them if they attempt to navigate to it.

Satisfies

#201

NOTE: In order to see this feature, I had to comment out the admin check on the layout.tsx due to perms being broken atm so you will likely have to do the same thing in order to check this.

[christianhelp]

It looks like my prettier run also reformatted files where I didn't touch stuff as a heads up