feat(waas-engine): add dynamic site config schema and slotId placement types

app/data/smtp.config.json

@@ -0,0 +1,10 @@
+{
+  "host": "smtp.placeholder.local",
+  "port": 587,
+  "secure": false,
+  "user": "placeholder@domain.de",
+  "pass": "****",
+  "fromName": "N&D IT Solutions System",
+  "fromEmail": "noreply@ndsolutions.de",
+  "isConfigured": false
+}