Rename library target from "nibp_protocol" to "nibp_protocol-lib" , gate demo executable
- Replace manual FetchContent blocks for crc, c_helpers, and fw_update_protocol with FetchDependencies module
- Add LIB_DEMO_ENABLE option (default OFF) to gate the demo executable
- Drop -Wall -Wextra -Werror, if(TARGET ...) guards, redundant enable_language(C CXX) call
- Updated project.yml.in