feat(aquamqtt): enable overrides for messages emitted by main

[tspopp]

This PR enables overrides of the messages sent from MAIN to HMI

Features:

• Show SOLAR Icon within the HMI if AquaMQTT is running with flagPVModeHeatPump == 1
• Show PV Icon within the HMI if AquaMQTT is running with flagPVModeHeatElement == 1

Fixes:

• State Solar Input was misinterpreted as State PV Input

New MQTT Topics:

Main Message

Value	MQTT Topic	Format	Unit	Other Information
State: Solar Input Signal Detected	$root/main/stateSolar	bool

AquaMQTT / Statistics

Value	MQTT Topic	Format	Unit	Other Information
Active Overrides (MAIN)	$root/stats/activeOverridesMain	json		Active Overrides are flagged either with 1 (overridden) or 0 (not overridden) Example Payload: { "statePV": 1, "stateSolar": 1 }

Else

• Provided some more troubleshooting details and scripts
• Fixes #23