Add half-dome extragalactic components to PySM

[zonca]

here is the configuration for all the Websky components:
https://github.com/galsci/pysm/blob/main/src/pysm3/data/presets.cfg#L359-L396

those templates are stored here:
https://portal.nersc.gov/project/cmb/pysm-data/websky/0.4/

and here the documentation:
https://pysm3.readthedocs.io/en/latest/websky.html

The easiest way is to have those templates available for Halfdome as well.

[adrianbayer]

Tagging @lindablot who's been working on tSZ for HalfDome :)