Enable sharing for devservices

[kdubb]

Quarkus devservices implementations can support sharing, one or more, containers between running Quarkus applications. This should be enabled.

Adding support involves:

1. Add a property to enable disable sharing: quarkus.neo4j.devservices.sharing
2. Add a property for sharing service name: quarkus.neo4j.devservices.service-name
3. Label started container instances: quarkus-dev-service-neo4j with the value of the service name

In the devservices processor, if sharing is enabled, you first look to see if an existing container instance exists with label=quarkus-devservices-neo4j=<service-name>. If an instances has the required label & value, connect to that container instance, otherwise create a new container instance with the label & value.

Together, these allow a single instance (and using the service name multiple instances) to be shared between applications. However, each app can only be automatically configured to target a single instance.

[michael-simons]

Neat. I can start working on that November.