Clubhouse-148415: fix issue with interface nil not being nil

[jfbramlett]

Go interfaces...my initial attempt worked fine in some cases but didn't cover how we actually use this with our db queries. We create an array of "blank" interfaces that can hold any value (for Scanning into) - this results in one of those kind of weird situations in which a nil value is not really a nil so the checks I had were not working correctly.

This PR expands on the check to determine if the value is nil, I broke it into singular checks to make it a bit easier to debug and see which condition is being met. In this case I need to look at what the interface is referencing to determine if the value is nil (the check inside if reflect.ValueOf(val).Kind() == reflect.Ptr).

Its a bit ugly but so is Go reflection in general.

[shortcut-integration]

This pull request has been linked to Clubhouse Story #148415: Reloading an existing model does not update timestamp fields.