Bug resubmissions of final thesis shows old date (#113)

Previously if an author resubmitted their final thesis to the supervisor fora re-submission to the examiner the date of submission was the first submitted final thesis. And the status text only showed "Waiting for grading". This caused a lot of confusion for the authors when the dates and status of the final thesis was divergent from their perceived view of dates and changes.

Fixes #79

Reviewed-on: #113
Reviewed-by: Andreas Svanberg <andreass@dsv.su.se>
Co-authored-by: Nico Athanassiadis <nico@dsv.su.se>
Co-committed-by: Nico Athanassiadis <nico@dsv.su.se>

daisy-integration/src/main/java/se/su/dsv/scipro/integration/daisy/workers/RejectedThesisWorker.java

@@ -56,6 +56,7 @@ public class RejectedThesisWorker extends AbstractWorker {
                     if (supervisorGradingReport.getLastModified().before(rejectedDate)) {
                         supervisorGradingReport.setState(GradingReport.State.INITIAL);
                         supervisorGradingReport.setSubmitted(false);
+                        supervisorGradingReport.setDateSubmittedToExaminer(null);
                         supervisorGradingReport.setRejectionComment(thesisRejection.getMessage());
                     }
                 }