Remove pm2 to fix CLI failure

[LoicPoullain]

Issue

When using PM2, we get failures in the CI with a "exit code 7". This is not the first time it happens and I don't understand what the issue is.

Solution and steps

• [x] Remove PM2 and use another solution

Checklist

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