Handle Vallox update 2.0.20 changes

[karottenreibe]

With the latest update (https://www.vallox.com/en/myvallox/myvallox_2.0.20), Vallox added the ability to specify "off" as a new mode in the weekly schedule. It looks like this in the metrics:

  A_CYC_SCHEDULE_TUESDAY_21: 5,
  A_CYC_SCHEDULE_TUESDAY_22: 5,

The library should allow reading/setting this profile in the weekly schedule. AFAICT this just means renaming the "EXTRA" mode to "OFF". When I set A_CYC_SCHEDULE_TUESDAY_21 to client.PROFILES.EXTRA it shows the new off mode in that slot in the web UI.

When the ventilation unit is turned off via the "Enable" switch in the web UI, I see this in the metrics:

A_CYC_MODE: 5,

Maybe that's the way to detect if this new mode is currently enabled in getProfile()?