Add spin-up capabilities for `ClimaAtmos` simulations

[sriharshakandala]

For many climate simulations, it is necessary to run a simulation for multiple turn-over times before a statistically stationary state is reached and a usable start-up condition is achieved. For high resolution simulations, this start-up phase can be expensive. It is generally desirable to start the spin-up simulation at a lower resolution and gradually increase the resolution to the target resolution.

### Tasks
- [ ] Add capability to refine each spectral element into (4) spectral elements to help speedup spin-up simulations

Timeline estimate: About 3 weeks

cc: @charleskawczynski @cmbengue @tapios