ECR Pull Image input/output variable and/or Multi-tag

**Is your feature request related to a problem? Please describe.**
Ideally I would like to be able to multitag an image and push.
Would make it easier to tag if I could get the aws output variable of an ecr pull/push.

**Describe the solution you'd like**
either take the output variable of another push as input/without tag or allow pushs with multiple tags like azure devops docker

The issue names no source files, tests, or entry points. Start by locating the Azure DevOps tasks that implement ECR image pulls and pushes, then review how their inputs and outputs are defined and how Docker multi-tag pushes are handled. Done requires a clarified choice between passing an ECR output as the next task's input and supporting multiple push tags, with tests for the chosen behavior.

Written by the indexing model from the issue text.