Automatic configuration of main switch

[nao-pon]

After checking the ECHONET specifications, it seems that 0x80 is defined by the super class and can be set on many devices. If the Set property has 0x80, I think it's a good idea to automatically configure it as a switch entity. If you haven't worked on adding this feature yet, should I send you a PR?

[nao-pon]

I was able to do it relatively quickly, so I created a PR(#85).

[scottyphillips]

Only concern I have is around that 0x80 it’s not mandatory for it to be a set value, at least from my understanding of the English version of the spec. Perhaps we can allow users to decide, by either creating both a sensor and switch or a checkbox.

https://echonet.jp/spec_object_rp1_en/