Add coolix receiver

[glmnet]

Description:

This is a decoder for the coolix AC IR Transmitter component.

The idea is installing an IR receiver close to the AC unit's receiver, then listen for the same command one would send with the equipment's original remote control unit and figure out the state the unit is on.
This is not ideal as the code seen doesn't mean the device really turned into that configuration but I believe is pretty usable and useful.

I'm opening this as WIP as I did not test it much yet.

Two things I'd like feedback right now:

1. How can it be made (does it make sense) to be optional both transmitter_id and receiver_id, currently receiver_id is optional and I have to supply an id to the remote_receiver so I can link it. If I remove optional then user must have a receiver which is may be not the case, seamlessly if the user were interested only on the receiver part of this component the opposite situation can happen as is.
2. I guess I'd need to implement some remote_receiver muting when the component sends the code, I did not test this yet anyway so maybe this can be just ignored.

Related issue (if applicable): fixes

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#

Checklist:

• The code change is tested and works locally.
• Tests have been added to verify that the new code works (under tests/ folder).

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in esphome-docs.

[OttoWinter]

Agree the receiver_id is not perfect, but I also don't have a better way.

Even if we could make it auto-use a receiver in the config (if one exists), there would be the problem of how to de-select it manually (if the remote_receiver is for example for something else, like 433MHz signals).

[OttoWinter]

Looks good!

[glmnet]

LGTM (the author) haha I'm starting using this as I kind of hacked one of my AC units and put this next to the AC receiver and works great.
Docs: esphome/esphome-docs#288