Espeasy: Central command and event handling

Currently we have the possibility to receive commands from a number of sources.
For example:

• serial port
• p2p controller
• MQTT (Domoticz/OpenHAB)
• HTTP GET
• Rules

The problem is that there is no generic handler for receiving a command and executing it.
For example two MQTT controllers (C002 - Domoticz and C005 OpenHAB) do accept commands or events.
But both do have their own unique special handling for some plugins.
For some specific scenario's this can be a valid use case, but for most it is just code duplication and adding to the confusion why functionality differs among controllers.

So in short:

• Add (or choose) a generic command handler.
• Find a way to handle specific commands or events inside the plugin and not in the controllers.
• Proper detect whether something is an event or a command, so we don't have to use the "spaghetti method" to see what call may be successful in handling the incoming command or event.
• Evaluate demands for permission for some events or commands. (factory reset via MQTT doesn't sound like a good idea)