Add option for MQTT Auto Discovery subject to confirmation

Alternatively, one can use the python script rtl_433_mqtt_hass.py (see: rtl_433/examples/rtl_433_mqtt_hass.py at 6f7846e829cf9e9d6d27224ed8adb1f00f9f3a48 · merbanan/rtl_433 · GitHub).

Unfortunately, the format for naming devices and entities along with other config data differs from the format used by OpenMQTTGateway so this is not a perfect solution.

I wrote and posted PR for OpenMQTT Gateway that exactly solves this problem by allowing you to change the Discovery Prefix either from the WebUI or via
mosquitto_pub.

See:
PR:

and discussion under:
Add ability to change discovery prefix on the fly either via WebGUI or mosquitto_sub · Issue #1996 · 1technophile/OpenMQTTGateway · GitHub

For me at least, this truly solves the problem as I originally hoped!