* Add codename to version string and to bootloader title. * Use EDGETX_VERSION_SUFFIX instead of CODENAME * use "dev" instead of "merge" and "custom" instead of "SB". Changed to lower case for "nightly" and "release". * Show TEST BUILD warning screen for all non release builds. * Improved logic * Removed TEST_BUILD_WARNING, reverted to "merge" and changed to "selfbuild".