MQTT: add JSON fixed size 1D array support. WIP. Parsing array still broken.
<?xml version='1.0' encoding='utf-8'?>
<SVGHMI xmlns:xsd="http://www.w3.org/2001/XMLSchema" WatchdogInitial="10" WatchdogInterval="5" EnableWatchdog="true" Path="{name}" OnStart="chromium-browser --no-sandbox --test-type --single-process --start-fullscreen {url}"/>