Publish some base images together with Camel K

[nicolaferraro]

This is an idea we should develop more, but it's powerful!

It's not always necessary to do a build to create the base image for an integration, we may publish some base images in advance when releasing Camel K.

This would be really awesome in the future if we start to produce native compiled images, because users will just use them, without having to produce them (as it seems it requires a lot of time and resources).

In the Knative context, for example, we can produce native images containing:

• camel-runtime
• camel-knative
• camel-component-x

That image would be used automatically for the CamelSource-x, without requiring a new build inside Kubernetes.

The mechanism is useful also for standard JVM based images as it improves portability (does not require in-cluster build, that often require cluster-specific configuration).