v1.4.1433

• Fix #69 by improving import of custom reference sets in which there are missing custom field values
• Improve build process for uberjar to ensure backwards compatibility with JDK>=11
• Update to latest trud library as the NHS TRUD service now supports SHA256 for integrity checks on downloaded files
• Add intersect-ecl-fn to improve performance in data pipelines when an ECL expression may be re-used many times