Add RWTH provider (#1629)

* Add RWTH provider

* fix Owners order

* Reorganize RWTH Provider

* Fix staticcheck and code style issues

Co-authored-by: Tom Limoncelli <tlimoncelli@stackoverflow.com>

providers/rwth/auditrecords.go

@@ -0,0 +1,25 @@
+package rwth
+
+import (
+	"github.com/StackExchange/dnscontrol/v3/models"
+	"github.com/StackExchange/dnscontrol/v3/pkg/recordaudit"
+)
+
+// AuditRecords returns an error if any records are not
+// supportable by this provider.
+func AuditRecords(records []*models.RecordConfig) error {
+
+	if err := recordaudit.TxtNoMultipleStrings(records); err != nil {
+		return err
+	}
+
+	if err := recordaudit.TxtNoTrailingSpace(records); err != nil {
+		return err
+	}
+
+	if err := recordaudit.TxtNotEmpty(records); err != nil {
+		return err
+	}
+
+	return nil
+}