Create metrics protocol

[payamnj]

The application should sends domain logic and technical metrics to through the MetricsPort.
Should be designed with port and adapter methodology so the django user can overwrite their own metrics adapter in the django settings and by default we use just json structured logging (log based metrics)

Domain logics:

• user_enrollment (counter) labeled with course_slug and organization_id
• course_content_sent (counter) labeled with course_slig, contetent_id, organization_id
• user_activated (counter) labeled with course_id, org_id
• user_deactivated (counter) labeled with course_id, org_id, reason
• user_completed (counter) labeled with course_id, org_id
• quiz_submitted (counter) labeled with course_id, org_id, quiz_id, score, is_passed

Technical metrics:

• execution_time for commands (distribution metric)