Introduces a TESTNET variable to the Makefile and passes it from GitHub Actions workflows based on the chain-network input. Updates CMake build commands to include the TESTNET flag, improves help output formatting, and comments out unused genesis targets for clarity.
Changed build commands and artifact directories in macOS and Windows GitHub Actions workflows to use new target names and paths. Removed 'connectivity_tool' from CLI artifacts.
Renamed and reorganized CMake build profiles for consistency, removing unused Android, iOS, and MinGW profiles. Updated GitHub Actions workflows and Makefile to use new profile names and increased build parallelism for faster builds.
