[input_reader] Add structures to support composite devices

Add an InputDevice struct to InputInterpreter that
will hold all of a given device's information.
This will allow us to have an array of devices
from a single Hid endpoint, and it will allow
us to support composite devices.

It also allows us to add more device types by
only editing a single location in InputInterpreter

SCN-1251 #comment

Change-Id: I2bef76256b46771db4b1c19db9ffae7b82dec13c