Passing through collation options for case insensitive sorting

Steps to reproduce

Create a service, then attempt to sort case insensitively on one of the document fields

Expected behavior

Should be able to pass through collation options to be able to set the strength of the sort.

Actual behavior

No mechanism for passing through collation options

Suggested Fix

Addition of $collation or $options query param to allow passing through of collation options, similar to how $sort is passed through

System configuration

Tell us about the applicable parts of your setup.

Module versions (especially the part that’s not working): 5.1.0

NodeJS version: 8.4.0

Operating System: Ubuntu 16.04

Browser Version: Chrome 60

React Native Version: N/A

Module Loader: N/A

[chloeharper]

There’s two options to provide collation:

const collation = { locale: 'en', strength: 2 }
MyModel.find({}, null, { collation: collation });

or

const collation = { locale: 'en', strength: 2 }
const query = MyModel.find({})
query.collation(collation)

[superbarne]

@daffl this can be closed