Add support for select type entity

[koshisan]

Hi!
I hope this is the right spot for feature requests. I am using node-red to "emulate" devices in Home Assistant that either have no integration or have an integration I am not satisfied with. While it is way better than using Home Assistant helpers, options for the type of entity you can create are a bit limited. For example I am implementing a solution for my living room PC which is used for a fixed list of things (think "Netflix, VR, Steam") and I would like to activate the specific activity through Home Assistant.
However, currently only buttons and switches are implemented (and sensors - which cannot be set from HA at all).

I could create an helper in HA (which is what I have done for the meantime), but ideally I would have it under one device...