Provide a ServiceManager to shell scripts

[LoicPoullain]

Issue

When running a shell script, we often need to instantiate a ServiceManager to access services which is repetitive.

Solution and steps

• Pass by default a ServiceManager as second argument of the script function main.

Checklist

• Add/update/check docs (code comments and docs/ folder).
• Add/update/check tests.
• Update/check the cli generators.