Adapt rate_updates to multi-cells

[cguzman95]

Mentioned briefly in #125, rxn_data class misses some function to update rxn_solver_id and consequently difference cells (actually, it's set by default to zero and not updated, so when we do update_rata we are going each time to cell 0). I half-fixed it in #129 updating the same rate to all cells, but should be fixed completely in the future.

Since it needs some design on the main fortran code, I want to asign this to you, @mattldawson and avoid some possible re-design of my implementation.

[mattldawson]

sounds good - I may have some questions as I start working on this

[cguzman95]

Ok no problem. To do a suggestment, I think it should be something like when we create the update_rate object, send as an optional parameter the id cell that we want to set. Then, in the corresponding test create multiple rxn_update_data objects, each one with his own type, rate and cell