Implement Relude.Extra.Lens module

[chshersh]

This module should contain just very basic functions and types to work with lenses.

• Lens'
• lens
• ^.
• .~
• %~
• Juicy documentation with examples and usages

I personally think that lenses should be a part of base library. Fortunately, it's possible to implement small but extremely useful subset of lenses without extra dependencies. That's why packages like microlens exist. I think relude can have very small implementation of lens subset to be useful in many use-cases.

[cronokirby]

Should we aim for compatability with Lens or not? Otherwise opting for a profunctor based implementation would be a lot simpler.

[chshersh]

@cronokirby I would like for the solution to be compatible with libraries like lens and microlens. In my vision this should be possible. I need to discuss the implementation details with @vrom911 (because she is going to implement this), but otherwise we should be ok here 👍