Image Digest Reflection

[makkes]

This is an umbrella issue to track work around image digest reflection:

• Add image digests image-reflector-controller#214
• Supply digest of images that are selected by policy image-reflector-controller#87
• Support sha256 digest pinning image-automation-controller#165
• Add flux create image policy flag to set the digest reflection method #4244
• Add integration tests for ImagePolicy image-reflector-controller#445
• Add reconciliation interval to ImagePolicy image-reflector-controller#446

[vicaya]

Hope this get's done soon, as having to come up with sortable pre-release semvers in CI for dev and staging environments is a PITA. It'd be great if imagepolicy can do x.y.z-dev -> x.y.z-dev@sha256:foo -> x.y.z-dev@sha256:bar.