Improved code coverage (branches) around multipart file utils

- added test
- moved wrongly placed test (from MultipartFileUtilSpec to DataMapUtilsSpec)
- applied curent conventions to DataMapUtilsSpec

Issue-ID: CPS-475

Signed-off-by: ToineSiebelink <toine.siebelink@est.tech>
Change-Id: Ie8dc7f6802bb6ff0a256dc05df73da6af75409f3
2 files changed