[Device] Support for climate devices (thermostats / radiator valves)
Given that several people are requesting support for `climate` devices, I decided to make one central issue to discuss the implementation and post updates.

Related issues on GitHub:
* #32 Thermostat like the Eurotronics ones
* #37 Immax 07703L Radiator valve
* #39 Tuya Thermostat valve

It seems that these devices are best mapped as a [Thermostat service](https://developers.homebridge.io/#/service/Thermostat). In #32, @sjorge shared the mapping he uses in node-red.

Implementing a Service Handler for `climate` devices will probably bring support for the following devices (and their white label variants) to this plugin:
* [TuYa TS0601_thermostat](https://arno.dev/homebridge-z2m/devices/tuya/ts0601_thermostat.html): Radiator valve with thermostat
* [ETOP HT-08](https://arno.dev/homebridge-z2m/devices/etop/ht-08.html): Wall-mount thermostat
* [ETOP HT-10](https://arno.dev/homebridge-z2m/devices/etop/ht-10.html): Radiator valve
* [TuYa U86KWF-ZPSJ](https://arno.dev/homebridge-z2m/devices/tuya/u86kwf-zpsj.html): Environment controller
* [TuYa D3-DPWK-TY](https://arno.dev/homebridge-z2m/devices/tuya/d3-dpwk-ty.html): HVAC controller
* [TuYa HY08WE](https://arno.dev/homebridge-z2m/devices/tuya/hy08we.html): Wall-mount thermostat
* [eCozy 1TST-EU](https://arno.dev/homebridge-z2m/devices/ecozy/1tst-eu.html): Smart heating thermostat
* [Hive UK7004240](https://arno.dev/homebridge-z2m/devices/hive/uk7004240.html): Radiator valve
* [Hive SLR1b](https://arno.dev/homebridge-z2m/devices/hive/slr1b.html): Heating thermostat
* [Hive SLR2](https://arno.dev/homebridge-z2m/devices/hive/slr2.html): Dual channel heating and hot water thermostat
* [Leviton RC-2000WH](https://arno.dev/homebridge-z2m/devices/leviton/rc-2000wh.html): Omnistat2 wireless thermostat
* [Bitron AV2010/32](https://arno.dev/homebridge-z2m/devices/bitron/av2010_32.html): Wireless wall thermostat with relay
* [Centralite 3157100](https://arno.dev/homebridge-z2m/devices/centralite/3157100.html): 3-Series pearl touch thermostat,
* [Danfoss 014G2461](https://arno.dev/homebridge-z2m/devices/danfoss/014g2461.html): Ally thermostat
* [Eurotronic SPZB0001](https://arno.dev/homebridge-z2m/devices/eurotronic/spzb0001.html): Spirit Zigbee wireless heater thermostat
* [Immax 07703L](https://arno.dev/homebridge-z2m/devices/immax/07703l.html): Radiator valve
* [Stelpro ST218](https://arno.dev/homebridge-z2m/devices/stelpro/st218.html): Ki convector, line-voltage thermostat
* [Stelpro STZB402](https://arno.dev/homebridge-z2m/devices/stelpro/stzb402.html): Ki, line-voltage thermostat
* [Stelpro SMT402](https://arno.dev/homebridge-z2m/devices/stelpro/smt402.html): Maestro, line-voltage thermostat
* [Stelpro SMT402AD](https://arno.dev/homebridge-z2m/devices/stelpro/smt402ad.html): Maestro, line-voltage thermostat
* [Sinope TH1123ZB](https://arno.dev/homebridge-z2m/devices/sinope/th1123zb.html): Zigbee line volt thermostat
* [Sinope TH1124ZB](https://arno.dev/homebridge-z2m/devices/sinope/th1124zb.html): Zigbee line volt thermostat
* [Sinope TH1300ZB](https://arno.dev/homebridge-z2m/devices/sinope/th1300zb.html): Zigbee smart floor heating thermostat
* [Sinope TH1400ZB](https://arno.dev/homebridge-z2m/devices/sinope/th1400zb.html): Zigbee low volt thermostat
* [Sinope TH1500ZB](https://arno.dev/homebridge-z2m/devices/sinope/th1500zb.html): Zigbee dual pole line volt thermostat
* [Zen Zen-01-W](https://arno.dev/homebridge-z2m/devices/zen/zen-01-w.html): Thermostat
* [Moes BHT-002-GCLZB](https://arno.dev/homebridge-z2m/devices/moes/bht-002-gclzb.html): Moes BHT series Thermostat
* [Saswell SEA801-Zigbee/SEA802-Zigbee](https://arno.dev/homebridge-z2m/devices/saswell/sea801-zigbee_sea802-zigbee.html): Thermostatic radiator valve
* [Schneider Electric WV704R0A0902](https://arno.dev/homebridge-z2m/devices/schneider_electric/wv704r0a0902.html): Wiser radiator thermostat
* [Siterwell GS361A-H04](https://arno.dev/homebridge-z2m/devices/siterwell/gs361a-h04.html): Radiator valve with thermostat
* [Viessmann ZK03840](https://arno.dev/homebridge-z2m/devices/viessmann/zk03840.html): ViCare radiator thermostat valve