Simplify finding the integration command to use

[rytilahti]

The information about supported models is available in the integration classes, but it is hard to find which exact miiocli command to use.
A couple of ideas to make this more discoverable:

• Add output to miiocli info command responses
• Add new miiocli factory subcommand to return information about the class & direct command to use
• Add new miiocli device command that will initialize the correct integration, this is the most complex as it would involve constructing the available commands dynamically.

The fixing PR should also upgrade the README accordingly.