Track Issue creator separately from Reporter

Please add traceability to the user who actually created an issue. If the issue creator sets the Reporter field to someone other than themselves (for those users who have this privilege), there is no record whatsoever of who actually created the issue.

In addition to enforcing data integrity for people who might be abusing their privileges, we also want the ability to analyze how many issues are being created on behalf of the Reporter instead of by the Reporter.