Provide better error messages for payroll errors

[jniles]

Scenario

We had a case where two employee configurations were incorrect, and Vanga attempted to pay payroll. The system crashed with a generic error message (a NOT NULL error). After locating the issue with the employee in the database logs, we fixed that employee, but the users reported that the system still crashed.

In reality, we had fixed one employee, but were missing the second one. Had the users realized this, they might have been able to continue working by fixing the second employee.

Proposal

I propose we need better error messages for payroll crashes. We currently have everything in a database transaction, which is good, but we still need to keep some sort of log that to say "system crashed when processing employee jniles". That would provide some guidance to the user that something is wrong with employee jniles configuration. If we had this error message (instead of a NOT NULL error), there is a chance the payroll issues at Vanga would have worked themselves out yesterday without as much manual intervention from the team.