MediaPlayer: wait until device is ready after turning on or off

[AThomsen]

(Copy of #696 that was closed because stale with no further reason...)

When turning on some devices it takes some time before the device is ready to the next ir commands. Same goes for turning off the device.

With the current implementation scripting something like "turn on receiver and set input to hdmi2" requires adding a delay to the script between the two commands.

This PR adds two new device parameters: warm_up_delay and cool_down_delay that fixes this.

Another change is that delay is respected always and not only when sending command lists. BTW: why is delayset in the HA config.yaml instead of in the device descriptor files?

[snowyu]

warm_up_delay and cool_down_delay named delay_on and delay_off are more generic.

[AThomsen]

Yes, but I like the more specific names for this, as it is - well, a specific function. But I guess that's subjective.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.