CMake

[anton-seaice]

Add CMake build system

I plan to do this in the following order:

• Write CMakeLists to work for ACCESS-OM2 / auscom driver - see Add CMake Build #77
• Fix / update for ACCESS-ESM1.6 as part of merginging the access-esm1.6 branch into master
• Update spack package
• Update CI

[anton-seaice]

In #77 , support for a deterministic build to produce identical executables was skipped. Ill add now to the CMake build