Create docker image

[planetf1]

Create docker container which has

• egeria base image (set to same level as dependencies)
• this connector

Add support to actions:

• merge
• release

Following the same approach as used for HMS, Strimzi, and event schema repositories.

The intent is to make it easier to deploy a specific container for a dedicated egeria platform and server.
This request was brought up in the cloud native workgroup for those other repositories as offering value short term.

It's still possible to use the jar directly, and there is still a request for an uber-container with all connectors.

@cmgrote ok with you if I add this?

Now, in support, I note most of our repos are gradle based. I suggest making a switch to gradle build as a prereq for this. (I can propose a PR if you're ok with it in principle?)

[cmgrote]

Definitely fine with both, and also very appreciative of any PR's you want to send through with the changes 🙏