Implement new ISO names
At Debian BSP2024 @ Conova Salzburg, documented in https://github.com/grml/grml-live/issues/163 we decided on this new scheme:
4 components, joined together by "-"
- component 1 is statically "grml"
- component 2 is the flavour (small/full)
- component 3 is the version. Version is either a release version string (format YYYY.MM), or a prerelease version string (format preYYYY.MMrcN), or a daily version string (format dailyYYYYMMDDbuildNN)
- component 4 is the architecture (= debian arch, either amd64 or arm64)