Support image name and tag with digest file

[loicgreffier]

Currently, Jib is supporting the generation of an image digest file (Cf. Extended Usage) with the following format sha256:ba7816....

It could be helpful to support the image name with digest (my-org/my-image@sha256:ba7816...) and the image name + tag with the digest (my-org/my-image:1.0.0@sha256:ba7816...).

Kaniko is supporting it through the flags --image-name-with-digest-file and --image-name-tag-with-digest-file.

[loicgreffier]

@lqiu96 Interested in contributing, with some guidance

[lqiu96]

Awesome, thanks for your interest! We do welcome contributions from the community. Unfortunately, I am not the most familiar with Jib. CC'ing a few folks who may be able to provide you better guidance @ldetmer @mpeddada1