Changes

contrib/ci.inria.fr: only trigger nightly builds when running in the official extended job

This trigger is harmless since the job won't run unless somebody
manually specifies the branch name parameter.
But this commit is a baby step towards merging basic and extended jobs
into a single pipeline (and we won't trigger the basic job).

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>
(cherry picked from commit 94562e3d38f5b3e9837b208cd57e6fb4fd28d873)

contrib/ci.inria.fr: merge basic+extended Jenkins pipelines

Use a single pipeline that enables debug/coverity/mingw/...
depending on whether we are in the official basic or extended jobs,
or on whether some envvars were passed in custom jobs.

By the way, add some verbose messages showing what's enabled or not.

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>
(cherry picked from commit 4190f90f122f5badaed00762eff5e8ab3c624f46)

contrib/ci.inria.fr: fix buggy conflict merge in previous commit

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>