PeSIT server answers "database error" when no rule matches the requested file

Summary

In the PeSIT server, transferHandler.getRuleByName treats a "not found" like any database failure: the peer receives an internal-error diagnostic with the text database error, and the log says Failed to retrieve rule: record not found. On a production deployment this sent the operators looking for a database problem when the peer had simply named a file (PI 12) that matched no rule.

Expected

An unknown rule is a parameter error of the caller: diagnostic CodeParameterError with an explicit message, and a log line naming the rule looked up and its direction.

Test

TestGetRuleByNameNotFound.