Improve error message in studies_dispatcher

[pcrespov]

An error like this shows either as Internal Error with redirection or a strange front-end message from

File "/home/scu/.venv/lib/python3.9/site-packages/simcore_service_webserver/studies_dispatcher/_studies_access.py", line 187, in copy_study_to_account
    await copy_data_folders_from_project(
  File "/home/scu/.venv/lib/python3.9/site-packages/simcore_service_webserver/storage_api.py", line 112, in copy_data_folders_from_project
    raise web.HTTPServiceUnavailable(reason=msg)
aiohttp.web_exceptions.HTTPServiceUnavailable: Cannot copy project data in storage: {'errors': [{'code': 'HTTPNotFound',
             'field': None,
             'message': 'The file '
                        '3f4ea128-319d-11ec-8033-02420a0b2de3/a27085d9-6582-4dac-bf5d-73b2f03ded6f/work.zip  '
                        'in production-simcore was not found',
             'resource': None}],
 'logs': [{'level': 'ERROR',
           'logger': 'user',
           'message': 'The file '
                      '3f4ea128-319d-11ec-8033-02420a0b2de3/a27085d9-6582-4dac-bf5d-73b2f03ded6f/work.zip  '
                      'in production-simcore was not found'}],
 'message': 'The file '
            '3f4ea128-319d-11ec-8033-02420a0b2de3/a27085d9-6582-4dac-bf5d-73b2f03ded6f/work.zip  '
            'in production-simcore was not found',
 'status': 404}

SEE these rror logs for more details
https://monitoring.osparc.io/graylog/messages/graylog_139/c2bc9a00-38f0-11ed-b596-0242ac12000e
https://monitoring.osparc.io/graylog/messages/graylog_139/c2bc4be0-38f0-11ed-b596-0242ac12000e

[pcrespov]

Using error pages now and recently improved UI as well. in #5296