Matching semantic version constraints should look through local images first before trying to list a remote registry

[mozesl-nokia]

With the current implementation, when a semantic version constraint is given for the tag of the mutator/validator function, kpt will always try to list the available tags from a remote.

Instead, kpt should list local tags first, foregoing the need for network usage, then list remote tags if no matching ones are found locally. This also helps with testing out in-progress versions of functions.