Adds residual gas damping and additional molecular species to the residual gas calculations. The gas scattering and gas damping are now tracked separately for each species in an excess gas sub-budget. The damping calculation is done in the infinite volume limit by default but adds corrections for squeezed film damping if specified in the yaml file. The aLIGO excess gas sub-budget is shown below as an example.
The new yaml file fields are explained in this comment. The yaml files in this merge request are simpler and none of the interferometers include squeezed film damping.
For aLIGO, Aplus, and Voyager, H2, N2, and H2O are considered. The numbers for aLIGO are taken from the link in this comment. The numbers for Aplus and Voyager are copied from aLIGO and should be checked. The Cosmic Explorer interferometers additionally consider CO2 and Ar.
