MM-53107 Add setting to limit the max number of markdown nodes (#24414)

* MM-53107 Add setting to limit the max number of markdown nodes

* Add extra validation for a couple config fields

* Add new setting to telemetry

server/i18n/en.json

@@ -8643,6 +8643,10 @@
     "id": "model.config.is_valid.ldap_username",
     "translation": "AD/LDAP field \"Username Attribute\" is required."
   },
+  {
+    "id": "model.config.is_valid.link_metadata_timeout.app_error",
+    "translation": "Invalid value for link metadata timeout. Must be a positive number."
+  },
   {
     "id": "model.config.is_valid.listen_address.app_error",
     "translation": "Invalid listen address for service settings Must be set."
@@ -8863,6 +8867,10 @@
     "id": "model.config.is_valid.tls_overwrite_cipher.app_error",
     "translation": "Invalid value passed for TLS overwrite cipher - Please refer to the documentation for valid values."
   },
+  {
+    "id": "model.config.is_valid.user_status_away_timeout.app_error",
+    "translation": "Invalid value for user status away timeout. Must be a positive number."
+  },
   {
     "id": "model.config.is_valid.webserver_security.app_error",
     "translation": "Invalid value for webserver connection security."