[unifi] New site, wlan, wiredClient, and poePort. Discovery support (#11959)

[unifi] New site, wlan, wiredClient, and poePort. Discovery support (#11959)

* [unifi] New wiredClient and poePort, Discovery support

This change adds the following changes:
- 2 new things: a wired client and POE port.
- Adds discovery of clients and poePort.
- Adds guest channel to client thing.
Also included some refactoring and bug fixes.

This change includes changes made by Matthew Bowman that he created on his own branch but were never completed.

Closes #9609: Implemented async http call, which should fix the buffer overflow.
Closes #10375: At least should avoid the stack overflow.
Closes #11964: cid will be handled in lower case.

* Removed type from UniFiCache constructor

It's redundant and only used for logging.

* Added UniFi Site and wLAN things

* Improved default state handling

Updated refresh/state update, to also update when no data available.
Simplified usage of cache: call cache directly instead of implicit via controller class.
Made getDefaultState generic to all things, and simplified passing channelId instead of channelUID to sub methods.

* Moved dto objects to dto package.

* Added support for client experience

* Made fields private

No need to have them protected.

* Added PoE power-cycle command

Also added wireless client as command as this better fits with the openHAB model to handle commands that are only one way and not have a state.

* Updated readme

* [unifi] Added client/guest count to wlan

* Fix QRcode construction and added hidden ssid support in qrcode string

Also-by: Matthew Bowman <mgb@otr.mx>
Signed-off-by: Hilbrand Bouwkamp <hilbrand@h72.nl>
Co-authored-by: Matthew Bowman <mgb@otr.mx>