#135 IdentifiedPatientFetcher code does not consider multiple MRNs

[Girish Chavan]

When looking up patients by MRN, zero results generally come up. The reason being that the backend code seems to look for an exact match in the MRN column of IdentifiedPatient table. Most patients have more than one MRN in the column separated by a comma, so they would never match a single MRN if an exact match is done.
There is a MRNPatientMap table that maps MRNs to patients. It might be faster to search this table rather than search the identifiedpatient table using a LIKE query just for MRNs.

The problem is that MRNPatientMap is not yet a TIES standard table, but a Pitt specific extension.