Allow targets from using oci.pull() to be used anywhere an oci_push() target can be used.

Both rules result in a target that names an image, but they are not interchangeable when referring to an image by a "name". For an example of where this is relevant, see: https://github.com/abrisco/rules_helm/issues/206

There is already a precedent in `oci.pull()` and `oci_image()` being somewhat interchangeable when referring to images as content, but when something needs a name things aren't so clean.

Start by comparing the target interfaces exposed by oci.pull(), oci_image(), and oci_push(), then read the linked rules_helm issue for the naming use case. Done means a target produced by oci.pull() can be passed anywhere an oci_push() target can currently be used, including contexts that require an image name.

Written by the indexing model from the issue text.