Validate dedicated engine schema

Validate dedicated engine schema object, check for errors. Additionally, to the basic checks done by the CRUD endpoints, this endpoint checks that:

• The declared engine_output_ids are unique across the whole schema
• The mapped Queue datapoints (via schema_ids) are of the same type as the declared type
• The mapped Queue datapoints of enum type have exactly the same option values declared
• Different shapes of datapoints are not mixed together
• The mapped Queue datapoints of Multivalue-Tuple fields are of the same grid/freeform type
• When mapping to a single Multivalue-Tuple field, all the datapoints mapped from one Queue must come from a single tabular datapoint
• Multiple fields do not link to the same Queue Datapoint
• A mapped field either maps a Queue Datapoint with null/empty rir_field_names or the engine_output_id matches one of the mapped rir-namespaced rir_field_names (prefixed by rir: or nothing)

Returns 200 and error description in case of validation failure.