Use ClimaUtilities.jl Checkpointer module

[juliasloan25]

https://github.com/CliMA/ClimaUtilities.jl/issues/7

Switch from using ClimaCoupler.jl Checkpointer module to using shared ClimaUtilities.jl Checkpointer.

tracked by https://github.com/CliMA/ClimaUtilities.jl/issues/39

To Do

• [ ] Move get_model_state_vec from Checkpointer to Interfacer in ClimaCoupler.jl
  • Or just keep in Checkpointer if not deleting?
• [ ] Add general checkpoint_models function to Coupler Checkpointer
  • Combine Fields of p to a FieldVector, call ClimaUtilities.jl checkpoint function using that
• [ ] Update changed function usages
• [ ] Update files using ClimaCoupler.jl Checkpointer to load ClimaUtilities.jl module instead
• [ ] Test