Isochrone & Stellar modeling services

We could include interfaces to web services that provide isochrone model sets, such as MIST, Padova, Yale, etc.

We've mentioned this [before](https://github.com/astropy/astroquery/issues/954#issuecomment-991974614), but we didn't have an open issue for it.

The services I know of are:
* [ ] [MIST](https://waps.cfa.harvard.edu/MIST/)
* [ ] [Padova](http://stev.oapd.inaf.it/cgi-bin/cmd)
* [ ] [Yale](http://www.astro.yale.edu/yapsi/download_grids.html) (no web interface - they just let you download the grids)

If you know of more, please add them.

The fact that you can download and interpolate (some of) these yourself somewhat limits the need for an astroquery service, but at least some of these modeling groups regularly update their grids with new models or new filter sets, so it is probably still worthwhile to support web access.

Review the linked MIST, Padova, and Yale resources and the earlier astroquery #954 discussion first. Determine which services expose usable web interfaces and define the query and results scope before implementation; completion would require agreed interfaces for the selected model sets and tests, none of which are specified here.

Written by the indexing model from the issue text.