Policy pattern matching with images missing default repo path

[Starkteetje]

Describe the feature
The current implementation for matching a rule pattern to an image reference fails on the following case:

# pattern            # image reference
docker.io/test:* <-> docker.io/test:tag

The reason for that is: the pattern is matched against the fully qualified image reference, not the one given. Meaning in this case, the pattern docker.io/test:* is matched against index.docker.io/library/test:tag, which obviously fails. The reason for matching against the fully qualified reference is so that patterns like docker.io/* still match given images like redis.

For convenience reasons, I'd still be great, if the pattern docker.io/test:* would match docker.io/test:tag.