[RM-5654] Linemodel: orthogonalize continuum on usefull lines only

Created on 2020-03-06 14:31:06 by Didier Vibert. % Done: 0

Today, the masking or orthogonalization of the continuum is done on all the lines in the reference line catalog from parameter.json

this is ok for linemodel free|rules but not for tpl-ratio

=> if tpl-ratio: list all the non-null lines in all the templates catalogs, and mask/orthognalize only on these.