Metrics for startup and shutdown of services

[GitHK]

As a platform maintainer I would like to be able to reply to the following questions more easily:

• how much does it take for services to start or stop
• Are they slower than yesterday?

For these purposes I would like to have some metrics at my disposal, possibly a Grafana dashboard

### Tasks
- [x] Create metrics @GitHK
- [ ] https://github.com/ITISFoundation/osparc-simcore/issues/6416

[sanderegg]

completed. new issues will be opened for new needs.