Do not use setting for service point; use 'system' service point

Enhance fees/fines bursar report settings according to https://issues.folio.org/browse/UXPROD-2989 .

The setting for service point should not be used.

Instead of it backend should find a service point with 'system' code (case insensitive) and use it.

If such s.p. is not found then an error with full description of the situation should be reported and this fees/fines bursar report generation fails with this error.