Turn "keys" option into an attrset of attrsets.

This now provides options for each key and also converts old style
string-only keys into the new format while emitting a warning.

At the moment only the "text" option is actually supported.

For applying the keys for string-values the permissions attribute is set
to "0600" instead of the default value "0640" in keyOptionsType in order
to correctly replicate the old behaviour even when we implement
permissions and ownership.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Fix VM tests for hetzner and none backends.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
(cherry picked from commit 66aeeb201446a94f7ebb59461b5efcbc02019a9d)
tests: Add Archive::Cpio to all the coordinators.

This is needed in order to build the initrd for the target machines and
we don't have access to external network resources within the VM test.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
(cherry picked from commit 1bd7182bc1609d602e6193ee4665a6dce45aded4)
tests: Disable packet filtering on all VM tests.

This is only a source for more errors, confusion, more complexity and we
really don't want to test the packet filter here, because we already
have tests in NixOS directly.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
(cherry picked from commit 8feb9223bc5d43517bf4acd93b89a84802d90d05)