Release of probe firmware 5080

• All platforms
  • Introduction of CI/CD pipeline for building firmware
  • Fix for ICMPv6 echo replies on systems with 32-bit pid_t (Graham Edgecombe)
• Software probes
  • The auto update functionality has been removed from the CentOS 7/8 RPM.
• Cleanup on v3 hardware probe to align with v4 and v5 probes.
  • Streamline build process for flash and USB firmware
  • Removal of unused software / functionality
  • Revert to stock OpenWRT insofar as possible
  • Code refactoring to remove duplicate implementation of LED behaviour
  • JSON style logging framework introduced, initially for process restarting
  • Filesystem bug fixed that prevented release of flash firmware