Simulation output utils are absent from components API.

[iago-lito]

There were too many unresolved questions to properly extract post-simulation processing utils from #87 into #131 before we submit the paper and publish the repo.
This is an unfortunate and undesirable regression.
These utils need to be featured again.

Make sure to discuss, solve these in this context:

• Sanity checks for simulations: disconnected species, extinct species & disconnected graphs #151
• Extend extinct_species() #110
• Make subfunctions for trophic structure analysis #111
• Simulation output utils: only alive species? #112