Bump bulk export job request length

[pepsiofficial]

The REQUEST column on table HFJ_BLK_EXPORT_JOB is currently 500 characters, which is not long enough for verbose, complex queries, such as those involving the _typeFilter

Environment:

• HAPI FHIR Version: 5.5.0-PRE5-SNAPSHOT
• OS: MacOS 11.1
• Vivaldi (Chromium-based)