add the ability to specify inline replacements similar to the patch functionality #1537
Description
The kustomize controller already support inline patch declarations: https://fluxcd.io/flux/components/kustomize/kustomizations/#patches.
It would be helpful if the controller would also support inline substitutions, since this is a key feature of native kustomize (certainly since they will be sunsetting the variable substitution in future versions). Details can be found here.
There is postbuild variable substitution by the controller, which could cover this functionality, nevertheless I rather prefer to have to option to leverage first native kustomize features before having to fall back to functionality provided by the controller.