Some error messages are hard to understand and process

[pombredanne]

I scanned docker://docker.elastic.co/elasticsearch/elasticsearch-oss:7.10.2 with a docker pipeline. There are errors and they are hard to make sense of:

DiscoveredPackage 	One or more of the required fields have no value: type, name, version 	{'md5': None, 'name': None, 'purl': None, 'sha1': None, 'size': None, 'type': 'jar', 'sha256': None, 'sha512': None, 'parties': [], 'subpath': None, 'vcs_url': None, 'version': None, 'keywords': [], 'copyright': None, 'namespace': None, 'root_path': None, 'extra_data': {}, 'qualifiers': {}, 'descri… 
``

(I know what these are.... but a regular users would not)
To help a little, we should add at least the path that triggered such error

[tdruez]

The path of the resource is now included in the error.
See #338 for improvements on the error messages.