Integrations query variables - rework

[PhilipSkinner]

The current design assumed that query and body params are going to be configured and identified within the same collection, this is incorrect.

The current structure for configuring query parameters is:

{
  "variables": [
    {
      "name": "id",
      "type": "queryParam",
      "description": "The ID of the post to fetch"
    }
  ]
}

This needs to change to the following:

{
  "queryParams": [
    {
      "name": "id",
      "description": "The ID of the post to fetch",
      "required" : true
    }
  ]
}

Implement this new structure, and also implement the new {{required}} query parameter logic so optional query parameters can be constructed.

[PhilipSkinner]

Done, pushed into latest.