streamline docker image deployment and mvn deploy using GHA

[jeanetteclark]

Right now, we have 4 docker images for metadig-engine. In the metadig-engine repository, containers for metadig-scorer, metadig-scheduler, and metadig-worker are built. In metadig-webapp, the metadig-controller image is built. The controller image is dependent on metadig-engine being deployed on the maven.dataone.org repository, which is (currently) deployed to manually via mvn deploy.

In order to make sure that all of the images are using the correct (and the same!!) version of metadig engine we need to adjust the github action such that:

• deploy to maven.dataone.org using github actions at certain events (push to develop, tags)
• build the images from metadig-engine
• trigger a build of the image from metadig-webapp, possibly through a webhook

Only question I have here is whether deploying to the repo is a good idea, since I'll have to put an ssh key into a secrets variable for the action. Is that too powerful of a credential to trust to GHA @mbjones ?