Some LYWSD03MMC fixes

[gdyuldin]

LYWSD03MMC thermometer has similar API, but with slight differences. These patches fixes:

• Battery level indication
• Time get/set

Also it allows to:

• Reduce connect/disconnect to device to retrieving different data
• Retrieve and parse history data

[h4]

Thanks a lot for help. Its very impressive!

I'll look into changes little bit later and merge it.