[Feature] Tags on default consul.service.consul registration

#### Feature Description

Make it possible to set service tags on the default service created for consul servers. This is already possible on [Vault](https://developer.hashicorp.com/vault/docs/configuration/service-registration/consul#service_tags) and [Nomad](https://developer.hashicorp.com/nomad/docs/configuration/consul#tags) but not Consul, unless I'm blind.

#### Use Case(s)

In our usecase it would make it easier to hook up the Consul UI to Traefik using the Traefik [Consul Catalog provider](https://doc.traefik.io/traefik/routing/providers/consul-catalog/).

Start by tracing how the default consul.service.consul registration is created and compare the service-tag configuration documented for Vault and Nomad. Done means Consul can configure tags for its default service and those tags are visible to the Traefik Consul Catalog provider.

Written by the indexing model from the issue text.