Decide how to handle modules that embed their data in the child info.

For example, the dimmer in KS240 has these in the info response:

'fade_off_time': 1,
'fade_on_time': 1,
'gradually_off_mode': 1,
'gradually_off_mode': 1,
'max_fade_off_time': 60,
'max_fade_on_time': 60,

instead of when the reporting is done through a separate module like

Originally posted by @rytilahti in #764 (comment)