Incorporate Prometheus telemetry in version.gitlab.com data

We should add Prometheus related information to the version.gitlab.com ping, so we can gather more information about how it is used, and how widely.

We should add 6 new entries:

Boolean (or count 0 or 1) if Prometheus monitoring is enabled (server setting): prometheus['enable']
Number of Exporters enabled (server settings): Count of following flags true:
- node_exporter['enable'],
- postgres_exporter['enable'],
- redis_exporter['enable'],
- gitlab_monitor['enable']
Number of Projects on the server with the Prometheus Service marked as Active