This ticket will incorporate psf-matched coadds into DRP and include the following:
1) Develop plan for processing Psf-Matched coadds as part of DRP including interface in pipe_tasks commandline tasks, and butler data product naming convention and mapped filesystem paths: https://community.lsst.org/t/who-are-the-stakeholders-for-psf-matched-coadds/1439
2) RFC plan.
3) Add new data products to appropriate mapper files, including getting input on ones with unique file paths like obs_subaru and obs_sdss.
4) Edit command line tasks (currently WarpAndPsfMatch, MakeCoaddTempExp, AssembleCoadd) to treat psf-matched and non-psf-matched coadds as separate entities.