Adjust endpoint calling documents during applicationrequest of company

[MaximilianHauer]

###Precondition:

• Create a dedicated endpoint for the applicationRequests that enables a CX-Operator to access docs from other companies  portal-backend#1070

Current Behavior

• wrong endpoint is called during the application request. Rendering the CX-Operator unable to access the registration documents provided by the applicant.

Expected Behavior

• CX-Operator should be able to download the documents from an applicant company.
• replace document endpoint of details page in https://portal.int.catena-x.net/applicationRequests to GET: /api/registration/documents/{documentId}

Steps To Reproduce

1. Open a application of a company in https://portal.int.catena-x.net/applicationRequests by clicking on the details
2. try to download the document in the details