Add new MQTT message will JSON containing all available info about failed tasks

[mountaindude]

Is your feature request related to a problem? Please describe.
The current MQTT message that is (optionally) sent when a task fails or is reloaded only contains the app name.

Describe the solution you'd like

• Add new MQTT message topic (configurable in config file) in which the full JSON will be sent
• Leave current MQTT topic as-is

As the new message is sent on a new topic this will be a non-breaking change.

[mountaindude]

Included in coming 5.0 release.