Help: Transform CMAKE_SYSTEM_NAME tables into lists

Changes:
- Added some initial operating system family categories (Apple, UNIX,
  Windows).
- Used list instead of table. Unlike the tables, lists provide
  documenting additional info and CMake versions.
- Added CMake versions to most values where they were introduced or
  could be determined from the Git log.
- Additionally added the OHOS value to the list (introduced via #25987)
- Emscripten name was used by toolchain files also before CMake 4.2 but
  documented with this version.