Allow HOT_WATER device types

[eko]

Two things in this pull request:

• Added a new type to specify device type (HEATING, HOT_WATER) in the metrics labels
• Support HOT_WATER device type response APIs

Here is an example output for HOT_WATER:

[2021-10-03T10:07:40Z INFO  tado_exporter] starting tado° exporter on address: 0.0.0.0:9898
[2021-10-03T10:07:40Z INFO  tado_exporter] waiting for the first tick in 10 seconds...
[2021-10-03T10:07:50Z INFO  tado_exporter::tado::client] retrieving zone details for Bureau...
[2021-10-03T10:07:50Z INFO  tado_exporter::tado::client] retrieving zone details for Cuisine...
[2021-10-03T10:07:50Z INFO  tado_exporter::tado::client] retrieving zone details for Salon...
[2021-10-03T10:07:50Z INFO  tado_exporter::tado::client] retrieving zone details for Chambre...
[2021-10-03T10:07:50Z INFO  tado_exporter::tado::metrics] -> Bureau (HOT_WATER) -> setting temperature (celsius): 55
[2021-10-03T10:07:50Z INFO  tado_exporter::tado::metrics] -> Bureau (HOT_WATER) -> setting temperature (fahrenheit): 131
...

[cristicalin]

Just tested this on an account with a hot water controller and it solves the issue.

[eko]

Great, thank you @cristicalin!