Use ECR feed for OCI and docker

[eddymoulton]

ECR supports more than just container (docker) images as it's a fully featured OCI registry.

To allow support for this we can query the manifest before we download/pull the image to switch between our pre-existing support for OCI feeds and docker feeds.

This approach means that users must have some pre-existing knowledge about the package when selecting from an ECR feed as it could be a helm chart, container image or any other OCI artifact type. It is worth nothing that currently we do nothing to filter out non-docker images from the search and any helm charts in ECR would appear as options when deploying a container - but would simply fail to deploy.

[[sc-75291]]

This should not be merged with the feature toggle in place until this server PR is merged: https://github.com/OctopusDeploy/OctopusDeploy/pull/30162