Issues in json formats

[dosse]

1. It must be possible to omit the attachment relationship of referential metadata attributes defined in the dsd, as those cannot always be fixed to either the dataflow, a fixed dimension group or observation level. Often more flexibility is required when attaching individual referential metadata values at runtime to whatever is required.
2. It must be possible to omit all dimension indexes of a key in the dimensionGroupAttributes object in data messages, e.g. "::::" as writers cannot always easily upgrade such attributes to the dataSet.
3. It must now be possible to omit dimension values in data messages if those transport only attribute or referential metadata values at dataflow level or partial key level, e.g. with parameters measures=none.
4. data message line 719: The definitions of dimension, attribute and measure values must be "anyOf" instead of current "oneOf":

   						"value": {
   							"oneOf": [
   								{"type": "integer"},
   								{"type": "number"},
   								{"type": "boolean"},
   								{"type": "string"},
   								{"$ref": "#/definitions/localisedText"}
   								]
   						},
   

   				"value": {
   					"oneOf": [
   						{"type": "integer"},
   						{"type": "number"},
   						{"type": "boolean"},
   						{"type": "string"}
   					]
   				},
   

   otherwise with e.g. the value = 6 (an integer but also a number) the validation fails.