Motivation:
The market-user api can handle varieties of http method request.
Integration tests are necessary to ensure that basic functionalities
of the controller are not broken when new functionalities are added.

Modification:

- add AccessDeniedException to the list of handled exceptions. This
    is accompanied with a test to check that it work as it suppose to.
- adjust the market-user controller:
    - post method to return 201, location url in the header and a json
          body that contain the newly create user
    - put method to return 200 if the uuid already exist or 201 if it
          is a new uuid.
    - get method now include sorting and some limiting value for the
         parameters.
    - delete method now comply with the standard.
    - use CerebrumEntityUuidGenerator.isValid to check the validity of a
        uuid and if invalid, CerebrumInvalidUuidException is thrown.
- add few sanity test to the main application test
- add various tests scenarios to cover all HTTP methods in the market-user
    controller.

Result:

New 41 tests were added which leads to improve test coverage for the
market-user API and some minor bug fixes.

Target: master
Acked-by: Franz Stephan
Review-at: https://gitlab.hzdr.de/hifis-technical-platform/helmholtz-cerebrum/-/merge_requests/24