Changes to Get Funding Info

added the optional property detail/items/ctx to the response with the 422 status

added the optional property detail/items/input to the response with the 422 status

the response property funding_rate became required for the status 200

the response property index_price became required for the status 200

the response property mark_price became required for the status 200

the response property next_funding_time became required for the status 200

the response property funding_rate became optional for the status 200

the response property index_price became optional for the status 200

the response property mark_price became optional for the status 200

the response property next_funding_time became optional for the status 200

endpoint added