[CI] Break out Build Push Containers to an action

[CalvinRodo]

Lots of search and replace w/regards to this: https://github.com/cds-snc/covid-alert-server/blob/master/.github/workflows/build-push-containers.yml

Risk: pipeline is less readable.

This action should do the following ac:

• [ ] Configure AWS Credentials
• [ ] Login to ECR
• [ ] Push a list of containers to that registry
• [ ] Logout

of ECR

[stephenyates-gc]

Will improve the readability of the CI pipeline.