Deprecate prometheus.listen_address and prometheus.enable

What does this MR do?

1. Replace prometheus.enable with prometheus.enabled to be consistent with other settings.
2. Replace prometheus.listen_address with prometheus.server_address to be accurate on what it does.

Towards #227111

Changes

1. Gitlab::Prometheus::Internal.server_address usage got put in the only place where it is used.

2. Gitlab::Prometheus::Internal.listen_address became Gitlab::Prometheus::Internal.server_address.

3. Gitlab::DatabaseImporters::SelfMonitoring::Project::CreateService.prometheus_listen_address became Gitlab::DatabaseImporters::SelfMonitoring::Project::CreateService.prometheus_server_address.

4. Gitlab::DatabaseImporters::SelfMonitoring::Project::CreateService.internal_prometheus_listen_address_uri became Gitlab::DatabaseImporters::SelfMonitoring::Project::CreateService.internal_prometheus_server_address_uri

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing