T3 should use Arkane YAML files where possible

[alongd]

After the 1st iteration, if T3 tries to compute a rate for a new reaction that involves one or more species that were already computed, it spawns all jobs related to that species, which is redundant and might take a lot of time.
Instead, it should always keep Arkane YAML file paths for each species it computed (thermo or one that participates in a reaction), and use these instead of spawning jobs for these species.