meson: ci: Convert some tasks to use meson

The Windows task is changed to use meson as there currently is no way to run
all tests in the old MSVC build system (only ninja is covered for now, we
don't have enough CI resources to test msbuild as well).

To maintain autoconf coverage, the Linux task is duplicated to test both meson
and autoconf builds (linux is currently the fastest task). FreeBSD and macOS
are also converted to meson, as it seems more important to have coverage for
meson than autoconf.

Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Author: Justin Pryzby <pryzby@telsasoft.com>

Author: anarazel