docs: Namespace GraphQL resolvers

[machikoyasuda]

Issue Description

GraphQL resolver JSDocs are not organized in http://api.docs.reactioncommerce.com/

Steps to Reproduce

Please provide starting context, i.e. logged in as a user, configure a particular payment method.

1. Go to api.docs.reactioncommerce.com
2. Try to find a GraphQL method.

Possible Solution

Add @namespace Accounts/GraphQLResolvers to the top of each file, once.
Add @memberof Accounts/GraphQLResolvers to each method that you want part of that namespace.
Change Accounts to whatever schema is the resolver deals with