ddns: store configuation in database (#435)

* ddns: store configuation in database

Co-authored-by: nap0o <144927971+nap0o@users.noreply.github.com>

* feat: split domain with soa lookup

* switch to libdns interface

* ddns: add unit test

* ddns: skip TestSplitDomainSOA on ci

network is not steady

* fix error handling

* fix error handling

---------

Co-authored-by: nap0o <144927971+nap0o@users.noreply.github.com>

pkg/ddns/dummy/dummy.go

@@ -0,0 +1,16 @@
+package dummy
+
+import (
+	"context"
+
+	"github.com/libdns/libdns"
+)
+
+// Internal use
+type Provider struct {
+}
+
+func (provider *Provider) SetRecords(ctx context.Context, zone string,
+	recs []libdns.Record) ([]libdns.Record, error) {
+	return recs, nil
+}