Scan Storage implementation for ClearlyDefined

[blaumeiser-at-bosch]

New feature: Enable the ability to get scan results from clearly defined in the ORT scan run. The idea is, that this is realized by a scan storage backend provider.

Issue here (similar to https://github.com/heremaps/oss-review-toolkit/issues/2211): It is difficult to store back the results at the end of the scan process because Clearly Defined only allows to trigger scans but not to provide scans.

Acceptance Criteria:

• [ ] ORT scan call retrieves scan results from Clearly Defined and processes them as if the scan had been executed locally.

Open Question: Is it necessary to download the raw results or a summary of the relevant information as already stored in Clearly Defined?

[mnonnenmacher]

I have done a proof of concept implementation for this a long time ago, but I think parts of it could still be reused now: https://github.com/heremaps/oss-review-toolkit/commits/clearlydefined

[blaumeiser-at-bosch]

@mnonnenmacher 👍 Sounds like a start