Add native-deb* targets to build native Debian packages

In continuation of previous #13451, this commits adds native-deb*
targets for make to build native debian packages. Github workflows
are updated to build and test native Debian packages.

Native packages only build with pre-configured paths (see the
dh_auto_configure section in contrib/debian/rules.in). While
building native packages, paths should not be configured. Initial
config flags e.g. '--enable-debug' are replaced in
contrib/debian/rules.in.

Additional packages on top of existing zfs packages required to
build native packages include debhelper-compat, dh-python, dkms,
po-debconf, python3-all-dev, python3-sphinx.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes #14265

.github/workflows/build-dependencies.txt

@@ -6,6 +6,9 @@ bc
 build-essential
 curl
 dbench
+debhelper-compat
+dh-python
+dkms
 fakeroot
 fio
 gdb
@@ -33,12 +36,15 @@ mdadm
 nfs-kernel-server
 pamtester
 parted
+po-debconf
 python3
+python3-all-dev
 python3-cffi
 python3-dev
 python3-packaging
 python3-pip
 python3-setuptools
+python3-sphinx
 rng-tools-debian
 rsync
 samba