Standardized build target names and artifact directory paths across Linux, macOS (Intel and ARM), and Windows GitHub Actions workflows. Updated Dockerfile to use 'gcc-linux-armv8' as the build target and added 'bison' to dependencies for improved build environment consistency.
Changed output binary names in CMakeLists.txt from zanod/simplewallet to lethean-* variants, with testnet-specific names when applicable. Updated GitHub Actions workflows to upload lethean-* artifacts instead of the previous explicit binary names.
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.
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.
