Fix Small Bugs (EditionID used as CohortID, Too Long URI, Person Search, Unhandled Declaration Hours)

Description

• Fixes the 3 bugs found by Stefan on Jan 23rd.
  • Request-URI Too Long when importing Training/Raise Requests.
  • Cannot offer positions to people who already have open applications
  • EditionID used as CohortID in FlexDelft export
• Unhandled declaration notification for teachers didn't exclude rejected applications

Related Issues

• N/A

Checklist

• I have added a changelog entry to reflect the significant changes I made.