Accept RabbitMQ Parameters Separately Instead of URL

[papaymaguire]

Currently the full URL must be used for the RabbitMQ connection. Rather split this up into separate parameters, host, port, user, password, etc, and create the URL from those. This will enable the Helm charts to accept several different parameters and to have the credentials come from Kubernetes secrets rather than hard coded in plain text. Once this is changed, an additional issue will be created in the charts repository in order to make that change.