[TTN] Add LoRaWAN-devices descriptor for TTNv3

[TD-er]

With an ESPEasy entry in the LoRaWAN Device Repository, it is extremely easy to add a new end device to the TTN v3 network.

This requires a number of YAML files, photo's and the decoder JavaScript (which we already have).

ToDo:

• [x] Check if ESPEasy must also become a member to the LoRa Alliance.
• [x] Take pictures
• [x] Add RN2483 (EU regional) profile
• [x] Add RN2903 (915 MHz regional) profile(s)
• [x] Create build-label dependent profiles (Model/Hardware rev/Firmware rev/Profile (region))
• [x] Validate payload formatter decoder JavaScript

[tonhuisman]

This can be closed, as the status is Fixed