Add new job and pipeline duration metrics

What does this MR do and why?

Describe in detail what your merge request does and why.

Add new gauges for job and pipeline durations: deployment_pipeline_duration_seconds and deployment_job_duration_seconds.

These metrics will hold the wall-clock duration of auto deploy pipelines and jobs.

gitlab-com/gl-infra/delivery#2891 (closed) and gitlab-com/gl-infra/delivery#2905 (closed)

Author Check-list

• Has documentation been updated?