Move from partition_info to config package

Now the kcrypt configuration will be just a block (`kcrypt`) in the regular
kairos configuration files.

We will use the config mechanism of looking up in multiple directories
becase the old code was only looking at `/oem` but at boot time
(initramfs) the configuration was present in `/sysroot/oem`.

The reason it "worked" was that we had a bug and a sealedvolume was
matching our request simply because we sent an empty UUID/Label/Name
and the sealedvolume had and empty UUID (empty matches empty, right?)

With that fixed on the challenger server side, it became obvious that we
never actually read the partition_info file because we were looking for
it at the wrong place.

Signed-off-by: Dimitris Karakasilis <dimitris@karakasilis.me>

pkg/config/suite_test.go

@@ -0,0 +1,13 @@
+package config
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestPartitionINfo(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Kcrypt config test suite")
+}