Trying to fix new issues with the CI system.

[slaff]

• clang-format-8: update the install.sh scripts to take care of this.
• nano_pb.py: failing again, find out why. (kudos to @mikee47 for fixing this issue).

[what-the-diff]

PR Summary

• Implemented new download command for clang-format-8
  A command has been added which is configured to download a specific version of a tool used in the code formatting process 'clang-format-8', and it's being stored in a particular location in the system (/opt/clang-format-8).

• Updated environment variable for clang-format location
  Changes made to the environment variable CLANG_FORMAT to ensure it points to the newly defined download location of clang-format (which is /opt/clang-format-8). This will help in making the tool easily traceable and accessible for the system whenever needed.

[mikee47]

@slaff nano-pb I've pushed a PR for that slaff/Sming-GoogleCast#3