support supplementary oneOf, anyOf, allOf, noneOf section in schema with valid 'type'

[andy-miracl]

If you have a schem with a valid type and also oneOf anyOf, allOf or noneOf, then defaults are not applied.

A typical use case is when you have an object schema that is required to have one field or another, but not both, (see https://stackoverflow.com/questions/24023536/json-schema-how-do-i-require-one-field-or-another-or-one-of-two-others-but-no). You can do this kind of thing with the following type of schema schema :

{
    "title": "test",
    "type": "object",
    "properties": {
      "obj1": {
        "type": "object",
        "properties": {
          "prop1": {
            "type": "string",
            "default": "val1"
          }
        }
      },
      "obj2": {
        "type": "object",
        "properties": {
          "prop2": {
            "type": "string",
            "default": "val2"
          }
        }
      }
    },
    "oneOf": [
      {
        "required": [
          "obj1"
        ]
      },
      {
        "required": [
          "obj2"
        ]
      }       
    ]
}

However, conflate does not apply the object property defaults in the case of json input data such as :

{
  "obj1": {} 
}

Conflate should output :

{
  "obj1": {
    "prop1": "val1"
  }
}

[andy-miracl]

If a schema has a valid type then it should apply the defaults.