[WIP] linkageclasses and deficiency of reaction network

[yewalenikhil65]

from #390

based on defintions of linkageclasses
and deficiency

[yewalenikhil65]

Thanks @isaacsas
Looks good now.
Next stop of network analysis should be about weakly reversible networks, and summarize functions that you were talking about. And somewhere we could fit deficiency theorems in all this.

[isaacsas]

@yewalenikhil65 made some modifications. In particular, I think deficiency requires enough inputs that it is better to expect users to pass the correct stuff, but make sure the docs show how to do this for an example (which I added). Having sparse in it just felt wrong, and it was getting too complicated in all the stuff it was sequentially calculating as kwargs.