Expose essential demand control data points

[Matze2]

Closes #183

It also depends on PR Apollon77/daikin-controller#268 .

For now only the minimum needed for later control is exposed:

• enabled: to be able to activate or deactivate demand control
• mode: to be able to change the modes MANUAL, AUTO (, SCHEDULE)
• max_power: to be able to change maximum power percentage of demand control

Not exposed:

• type: meaning unknown; and must be always 1
• schedule information: support is complex and is not really an automation use case in my opinion

Open Issue: at least "maxPower" (but possibly also "mode" and "enabled") will be writable later. In this PR they are placed in their own group "demandControl".
On the other hand, the current adapter bundles all writable data points within the "control" group.

With this PR I could replace the usage of "daikin-cloud.0..climateControl.demandControl.modes.fixed" in my dashboards.

[Matze2]

Hi @Apollon77, with the changes in daikin-controller I also updated this project in two ways:

• expose the type field of demand control also as variable
• to avoid "Data for channel demandControl missing!" messages in the protocol, we ignore if demand control data is not available (because of lacking support)

I appreciate if you time for review and feedback. Thanks in advance.