tests: add matrix-test for CI

This a new matrix inversion test written from scratch to be suitable for
running in CI: quick to run and automatically detects success/failure.

This all is a result of what I learnt while working on
https://gitlab.freedesktop.org/pq/fourbyfour



Computing the residual error with infinity norm comes straight from
fourbyfour documentation on how to evaluate matrix inversion error.

Most of the hard-coded test matrices have been generated with fourbyfour
project as well, as it contains the generator code. The matrices are
hard-coded here also to make testing faster, but primarily because the
generator code needs BLAS and LAPACK, and having those as Weston
dependencies would be far too much just for this.

Now, if someone wants to modify weston_matrix stuff, we should at least
detect matrix inversion and multiplication bugs.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>