Pre-fill Docker Swarm Service "Change container image" for easier version update

[bluepuma77]

Is your feature request related to a problem? Please describe.
I want to update my Docker Swarm service to a newer image version. Currently I need to manually select my private registry from the drop down and manually enter the image name and version.

Describe the solution you'd like
Portainer knows all the details already as the service has been created before. So it would be great if portioner would just pre-select the registry and pre-fill image name and version.
I assume the likelihood of changing registry or image (besides version) to something different is usually very low.

Describe alternatives you've considered
Alternatively Portioner could additionally pull a list of available images and pull a list of available versions from the selected private repository. That way no typo can happen and kill a production website when trying to deploy.

Additional context

[SvenDowideit]

YES PLEASE!!!