Adjust handling SimpleField to allow for invalid types default to string type
Add validation of SimpleField schema definitions and SchemaData instances
adding following new warnings:
-SimpleField has an invalid type attribute value [ATC 26]
-SchemaData contains a SimpleData value that does not correspond to the declared type [ATC 27]
-SchemaData has a schemaUrl attribute that is missing the required fragment identifier ("#") [ATC 27]
-SimpleData name not found in Schema [ATC 27]