[OData] recognize parameters in an x-www-form-urlencoded request body

[tusmester]

Currently we expect clients to send parameters in a json formatted body. Some actions are designed to work with a form-urlencoded request body:

FileName=abc.docx&ContentType=File&PropertyName=Binary

These actions also expect to have access to the Form values of the request, which is not possible, because the OData middleware reads the body which makes it impossible for asp.net to parse it, because the body can be read only once.

Solution

• if the body is formatted as x-www-form-urlencoded key-value pairs, parse it to a similar JObject as we do in case of a json string:
  

  sensenet/src/OData/ODataMiddleware.cs

  Line 357 in f731f79

  return ReadToJson(models);

• make these parameters accessible for the action method, most likely through the OperationCallingContext object.