feat: add profiling step functions

[guilhem-barthes]

Description

Allow transferring function profiling steps through the orchestrator, allowing the builder to register event without having to have http(s) requests to the backend api server (involving having access to the db to get credentials). This also allows having duration for the function available on every backend.

Still open on naming for the two new steps for the function. For now we have:

• build_image
• save_function

This does not include the API part for the frontend, which woudl be part of another task (FL-1518)

Fixes FL-1519

Companion PR

• https://github.com/Substra/orchestrator/pull/407

How has this been tested?

Checklist

• [ ] changelog was updated with notable changes
• [ ] documentation was updated

[linear[bot]]

FL-1519 Add function profiling steps