fix(aquamqtt): fixed various issues observed during the initial trial

[tspopp]

• Added MQTT Command reset to remove all overrides in MITM mode at once
• Added MQTT Topic activeOverrides which provides a status on all overrriden values in MITM mode
• Fixed Parsing of DHW's Installation Mode
• Fixed Parsing of Float Temperatures (Negative Values e.g. -0.1°C were broken)
• Fixed OTA and Unexpected Reboots due to Watchdog: Increased Watchdog Timer to 60 seconds
• Fixed MQTT Update Cycle: MQTT Topics are now only updated, when a change in the DHW message occur
• NTP Time Override in MITM mode is now optional and configureable within Configuration.h