feat: add author-restricted filter to errata creation endpoint

[RLRama]

Description

This PR adds a filter to the errata registering endpoint, so that only the creator of the original document may register an errata related to this document. Now, the POST endpoint should be as so:

• Route: /institution/{institutionId}/errata/create (unchanged)
• Route parameter(s): institutionId
• Request body:

{
  "description": "string",
  "documentId": 0,
  "healthcareProfessionalId": 0
}

Changes made

• Added a filter that retrieves the healthcare professional ID from the request body of the POST endpoint.
• Added a custom document repository (with a query that uses the retrieved healthcare professional ID), and modified the service and controller layers.