islandora_bagger_integration/bag_log REST endpoint fails on Drupal 9.4

[jefferya]

When the islandora_bagger is configured with register_bags_with_islandora: true, the REST call fails on the Drupal side.

I'll submit a PR once I've done further debugging and fixing the third error below.

The three errors I've discovered:

1. A change in for Drupal 9 required in the @RestResource annotation in IslandoraBaggerIntegrationBagLog.php. Details: https://www.drupal.org/project/drupal/issues/2802677#comment-13947261

 Client error: `POST https://cc-130.cwrc.ca/islandora_bagger_integration/bag_log` resulted in a `406 Not
   Acceptable`

2. jwt_auth instead of basic_auth (in README)

 {"message":"The used authentication method is not allowed on this route."}

3. Database insert problem

Drupal\Core\Database\IntegrityConstraintViolationException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'user' cannot be null

Consider in the jwt context change how the user is acquired: src/Plugin/rest/resource/IslandoraBaggerIntegrationBagLog.php L47
'user' => \Drupal::currentUser()->getAccountName(),