[RM-7529] add warning when 2nd pass window size is too small

Created on 2022-09-28 09:03:07 by Didier Vibert. % Done: 100

add warning when 2nd pass window size is too small

this can be checked, a posteriori, when the dz has been estimated: we should check that z_estim +/- dz is inside the window, if not, add a dedicated warning

MR: https://gitlab.lam.fr/CPF/cpf-redshift/-/merge_requests/495