[miio] Implement lumi devices support for gateways (#11688)

* [miio] Implement lumi devices support for gateways v3 WIP

Adding support for the following models:
* Aqara LED Light Bulb (Tunable White) (modelId: lumi.light.aqcn02)
* IKEA E27 white spectrum opal (modelId: ikea.light.led1545g12)
* IKEA E27 white spectrum clear (modelId: ikea.light.led1546g12)
* IKEA E14 white spectrum (modelId: ikea.light.led1536g5)
* IKEA GU10 white spectrum (modelId: ikea.light.led1537r6)
* IKEA E27 warm white (modelId: ikea.light.led1623g12)
* IKEA GU10 warm white (modelId: ikea.light.led1650r5)
* IKEA E14 warm white (modelId: ikea.light.led1649c5)
* Door lock (modelId: lumi.lock.v1)
* Aqara Door Lock (modelId: lumi.lock.aq1)
* Aqara Door Lock S2 (modelId: lumi.lock.acn02)
* Aqara Door lock S2 Pro (modelId: lumi.lock.acn03)
* Mi Smart Plug (Zigbee) (modelId: lumi.plug.mmeu01)
* Mi Temperature and Humidity Sensor (modelId: lumi.sensor_ht.v1)
* Mi Window and Door Sensor (modelId: lumi.sensor_magnet.v2)
* Mi Motion Sensor (modelId: lumi.sensor_motion.v2)
* Water Leak Sensor (modelId: lumi.sensor_wleak.aq1)
* Aqara Temperature and Humidity Sensor (modelId: lumi.weather.v1)

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* Work in progress support plug

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] cleanup, improve messages and initialization

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] Cleanup to prepare for PR

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] add missing placeholder

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] resolve merge issue

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] update readme after rebase

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] Update from review comments and warnings/checkstyle cleanup

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] update readme after merge and update json to updated format

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] Improve online indication

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* reset

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* Update readme

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] update from review comments

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

* [miio] feedback codereview

Signed-off-by: Marcel Verpaalen <marcel@verpaalen.com>

bundles/org.openhab.binding.miio/README.base.md

@@ -15,6 +15,8 @@ The following things types are available:
 | miio:generic     | Generic type for discovered devices. Once the token is available and the device model is determined, this ThingType will automatically change to the appropriate ThingType |
 | miio:vacuum      | For Xiaomi/RoboRock Robot Vacuum products                                                                                         |
 | miio:basic       | For most other devices like yeelights, airpurifiers. Channels and commands are determined by database configuration   |
+| miio:gateway     | Similar to basic, but with the Bridge feature, it can support to forward commands for connected devices                  |
+| miio:lumi        | Thing type for subdevices connected to the gateway. Note, these devices require a defined gateway to function            |
 | miio:unsupported | For experimenting with other devices which use the Mi IO protocol or to build experimental support                                                       |
 
 # Discovery
@@ -86,6 +88,7 @@ However, for devices that are unsupported, you may override the value and try to
 
 Note: Suggest to use the cloud communication only for devices that require it. 
 It is unknown at this time if Xiaomi has a rate limit or other limitations on the cloud usage. e.g. if having many devices would trigger some throttling from the cloud side.
+Note2: communications parameter is not available for lumi devices. Lumi devices communicate using the bridge/gateway.
 
 ### Example Thing file
 
@@ -95,6 +98,11 @@ or in case of unknown models include the model information of a similar device t
 
 `Thing miio:vacuum:s50 "vacuum" @ "livingroom" [ host="192.168.15.20", token="xxxxxxx", deviceId="326xxxx", model="roborock.vacuum.s4", communication="direct", cloudServer="de" ]`
 
+in case of gateway, instead of defining it as a Thing, use Bridge
+
+`Bridge miio:gateway:lumigateway "Mi Smarter Gateway" [ host="10.10.x.x", token="put here your token", deviceId="326xxxx", model="lumi.gateway.mieu01", communication="direct", cloudServer="de" ]` 
+
+
 # Advanced: Unsupported devices
 
 Newer devices may not yet be supported.
@@ -177,6 +185,9 @@ This will change the communication method and the Mi IO binding can communicate
 # Mi IO Devices
 
 !!!devices
+note: Supported means we received feedback from users this device is working with the binding. 
+For devices with experimental support, we did not yet confirmation that channels are correctly working. 
+Please feedback your findings for these devices (e.g. Are all channels working, do they contain the right information, is controlling the devices working etc.)
 
 # Channels