Merge branch 'feature/variadic-message-router' into development
# Conflicts:
# .gitignore
# include/etl/bip_buffer_spsc_atomic.h
# include/etl/version.h
# library.json
# library.properties
# support/Release notes.txt
# test/etl_profile.h
# test/runsanitychecks.sh
# test/runtests.sh
# test/vs2019/etl.vcxproj.filters
