Version 0.23 Cascoda SDK Release

Version 0.23 Cascoda SDK Release

Update OpenThread to a more recent upstream
Reorganize the documentation throughout the SDK
Reorganize SDK folders & targets to shorten path names
Rework low power Chili2 drivers
Add graphics library for the e-Paper display
Add driver for devboard buttons featuring short & long press detection
Add driver for PWM output
Add chilictl reboot command
Add chilictl flash full erase flag
Add date of last write for chilictl flashed binaries
Add flash region for KNX-IoT serial numbers and other manufacturer data
Various bugfixes and improvements