Factor out success handlers currently duplicated from the project core

I added copypasta of the current @personal-api/core success handler because I was bikeshedding over multiple solutions.

plugin-instagram/index.js

Lines 3 to 12 in 854b1c8

    
           const sendSuccess = (res, result) => { 
        
             const response = {}; 
        
             response.status = 'ok'; 
        
             response.result = result; 
        
             res.type('json'); 
        
             res.status = 200; 
        
             res.json(response); 
        
           };

The solutions I've been weighing are:

Pass in the success and error handlers. The plugin won't need to have any knowledge of the handlers.
Import a module containing the error handlers. The plugin will need to maintain the handlers as a versioned dependency.
?

	const sendSuccess = (res, result) => {
	const response = {};

	response.status = 'ok';
	response.result = result;

	res.type('json');
	res.status = 200;
	res.json(response);
	};