Add rudimentary parameter substitution model for Commands received by Devices.
For now, INCREASE/DECREASE actions received (legacy UI) are hard-coded but you can use a new syntax to express that you want the Command value itself substituted and the Device will pass it through to MiOS (see miosDimmerCommand.map, which needs to be attached to a Dimmer's binding via

    ...,command:MAP(miosDimmerCommand.map)