Changes to Retrieve client credentials

api tag Authentication added

added the non-success response with the status 400

added the non-success response with the status 401

added the non-success response with the status 404

added the non-success response with the status 500

added the optional property data/items/api_key to the response with the 200 status

the response property data became required for the status 200

the response property data/items/client_id became required for the status 200

the response property data/items/client_secret became required for the status 200

the response property data/items/created_at became required for the status 200

the response property data/items/deleted_at became required for the status 200

the response property data/items/environment became required for the status 200

the response property data/items/id became required for the status 200

the response property data/items/status became required for the status 200

the response property data/items/updated_at became required for the status 200