actions: add issue tracker action

This action will generate a summary page with bug counts and issues
counts for common labels.

The report will be pubished on
https://testing.zephyrproject.org/issues/zephyrproject-rtos/zephyr/index.html

Example:

https://testing.zephyrproject.org/issues/zephyrproject-rtos/docker-image/index.html



Signed-off-by: Anas Nashif <anas.nashif@intel.com>