Warn user about mismatching image filter annotations

[hiddeco]

Annotating HelmRelease resources with image filters can be tricky due to the fact that there is a difference between annotating top- and sub-level images (chart-image should be used for the former, <sub-level> should be used for the latter).

We can guide people in this by logging a warning in case we find an annotation that does not match a key from the values in the HelmRelease.

In extend we can also do this for Kubernetes native resources (Deployment, DaemonSet, etc), and warn the user when an annotation does not match any of the (init)Containers names.

[kingdonb]

No further enhancements can land in Flux v1,

• Flux v1 is in maintenance mode #3320