Adds query string serialization optimization

[akoenig]

👋

This PR introduces the serialization of the query string, when the explode attribute has been set. When defined the actual serialization includes a duplication of the parameter. Otherwise arrays will be serialized in a comma-separated way.

Example with explode turned off:

http://localhost:3004/api/robots?types=Droid%2CBot

Example with explode turned on:

http://localhost:3004/api/robots?types=Droid&types=Bot

This also activates the useQuerystring mode in request so that the query string gets encoded properly (#308).

I ran into the "problem" today, when using query string parameters which are typed as arrays and wanted to help to fix that. So this is my PR 🙂

[Alan-Cha]

@akoenig This is an awesome change!!! Thank you so much! We're in the middle of trying to get our 2.1.0 version out and I will try to get this in right after!

[papatego]

@Alan-Cha @akoenig how will this work when you have a nested object ?

> q = {filter: { first_name: 'hello', last_name: 'world'}}
{ filter: { first_name: 'hello', last_name: 'world' } }
> querystring.stringify(q)
'filter='