Investigate cleaning away some of the tools/ contents

[jimklimov]

Investigate (via complete test image) if removal of these is harmless for the ecosystem:

• astyle* files - might be deprecated in favor of zproject clang-format tests
• dbinit.h
• bios_agent++.* header template and script
• JSON.sh - also delivered by fty-core and probably should be extracted (from both) into a separate dependency package/repo - enter https://github.com/42ity/JSON.sh/tree/FTY-master (currently just a fork of my customized development, not packaged/integrated anyhow)
• builder.sh may have outlived its welcome