Stricter JSON schema for order actions

[ralienpp]

The current schema allows one to send actions that require parameters, but without actually including those parameters. Note that only actionId and actionType are mandatory:

"items": {
                            "type": "object",
                            "title": "nodeAction",
                            "description": "nodeAction",
                            "required": [
                                "actionId",
                                "actionType"
                            ],

This is probably because the schema wants to accommodate both cases with a concise schema. However, a stricter schema would be better, as it would make it more difficult for someone to send a message that is accepted by the schema, but is nevertheless logically incorrect.