With CAM-12718, we adjust the behavior of the task worker metric and need to change documentation accordingly

• independent from history level
• not affected by regular history cleanup
• has its own history cleanup
• tracks all assignees of all tasks, not just the one assignee visible at historic task instance upon metric creation
• it can be disabled

Places to add it to

• The database tables overview (add ACT_RU_TASK_METER_LOG table)
• Process engine configuration properties (new TTL for task metrics)
• Incorporate it into the Metrics section https://docs.camunda.org/manual/develop/user-guide/process-engine/metrics/
• User operation log (new log for the deletion of UTW data)
• History cleanup (clean up for task metrics can be configured)
• Migration Guide (additional data, opt-out possible, automatic clean up possible, manual metrics deletion now requires camunda-admin)