Generalize the response json format for operations

[travelist]

Currently [POST|GET] /api/v1/oprations/* APIs do not have the consistent json format. So let's modify the response format for example:
{ params: {constant_value: 1, target: [1,2]...}, outputs: [{id:1, name:"age"}, ...], success: true, ... }
for params, it will describe component-dependent values, for outputs, it will show the column indices and names for the next component.

This is just a idea, any ideas to improve this is appreciated.