set-event-listener: add auto-send interval

[uhppoted]

Add the auto-send interval to the set-events-listener and get-events-listener encodings and API functions:

• [x] uhppote-core
• [x] uhppoted-lib
• [x] uhppote-simulator
• [x] uhppote-cli
• [x] uhppoted-rest
• [x] uhppoted-mqtt
• [x] uhppoted-dll
• [x] uhppoted-codegen
• [x] node-red-contrib-uhppoted
• [x] uhppoted-nodejs
• [x] uhppoted-python
• [x] uhppoted-tunnel

[twystd]

Added auto-send interval to get/set-listener API functions throughout. Pending release v0.8.10