Bug: startupOrder not supported in Edge Device Model schema

[Metal-Mighty]

Expected Behavior

I should be able to specify the startupOrder parameter in the Edge Device Model schema in order for it to be applied in the Azure IoT Hub deployment

Current Behavior

The startupOrder parameter isn't supported in the portal's API endpoint body, it is ignored if you add it to the schema.

Steps to Reproduce

1. Get an existing Edge Device model schema or create a new one
2. Add a startupOrder parameter in the edgeModule parameters
3. Push the model to the portal
4. In Azure, the deployment model doesn't have the startupOrder parameters defined

Context (Environment)

Portal version:
LoRaWAN Stack version:

Logs

Additional Information

[judramos]

There is actually a bug when an edge model is created using API: the Json property name for properties is set with a lowercase letter, but when saving to Azure the first letter is capitalized. Then the list of modules is not recognized.
This problem is due to the following task: #3175 Moving usings to GlobalUsing.cs #3186, when the use of Newtonsoft.Json was changed to System.Text.Json on some models.