Fixed downloadFileFromUrl and unit tests
- HistoryUtils: the downloadFileFromUrl method now returns false when the response code is not equal to HTTP_OK and the unexpected response code is logged.
- HistoryUtilsTest: test the downloadFileFromUrl method with a valid and with an invalid URL.
- FileUtils: refactored the methods to create (temporary) files.
- FileUtilsTest: added some more cases to the testCleanFileName method and removed the local createFile method.