[OPENIDM-4283] Fixed bug in onUpdate for historical accounts sample.
[OPENIDM-4283] Fixed bug in onCreate for historical accounts sample.
[OPENIDM-4348] Added account enabling/disabling to historical accounts sample.
[OPENIDM-3997] Removed the back mapping in sync.json and the script it used, updated the README.
[OPENIDM-3997] Added sample for historical account linking.