Port 8080 is not a default splunk port, 8000 is.
Splunk web is a more acurate name for client communication on 8000

add rules for MongoDB cluster ports

Add rule for RabbitMQ

Add named rule for mongodb

Added entry for 8443, since we're allowing 8080

* Make use of name_prefix optional

* Code cleanups, add example

Using name_prefix instead of name to allow creation of duplicated with create_before_destroy (fix #40)

In order to avoid https://github.com/hashicorp/terraform/issues/18195