Fix/key backup in config script (#1206)

Because we provide the option to regenerate the config files, the encryption key could be lost.

- The configure.sh read the existing key and write it back during the config generation
- Backup the previously generated config files before overwrite it
- Fix invalid json output in the Extras field
- Reduce the error logs in case if the encryption key is invalid
- Response in the events API with valid user info in any cases
- Add extra error handling to the configure.sh. I.e. handle the invalid OpenID urls

infrastructure_files/management.json.tmpl

@@ -27,6 +27,7 @@
         "Password": null
     },
     "Datadir": "",
+    "DataStoreEncryptionKey": "$NETBIRD_DATASTORE_ENC_KEY",
     "HttpConfig": {
         "Address": "0.0.0.0:$NETBIRD_MGMT_API_PORT",
         "AuthIssuer": "$NETBIRD_AUTH_AUTHORITY",