[core] Extract subprocess calls into a function

[joaoantoniocardoso]

Since we are using more and more of this, with slightly different parameters, we would benefit from having it extracted into an ergonomic function to guarantee a coherent code to these critical parts of the system logic.

I think we can extract this into a function and share this code with core/services/autopilot_manager/mavlink_proxy/AbstractRouter.py:AbstractRouter::start and core/services/helper/main.py:ping.

Originally posted by @joaoantoniocardoso in #3154 (comment)