Add fallback to OGW drag precomputation

[ray-chew]

Problem 1: Fallback

Statement

Currently, we have artifacts for a few orographic gravity wave precomputed drag tensors, h_elem = 6,8,12,16,30,60. But outside these grid settings, any runs will error, and the user is required to run test/parameterized_tendencies/gravity_wave/orographic_gravity_wave/compute_preprocessed_topography.jl separately.

To-do

We need to:

1. Add a fallback where the preprocessed topography is automatically computed if the artifact is not available.
2. Add a switch so that the user can "force" the automatic precomputation in a run.
3. Move compute_processed_topography.jl from test/ to something more relevant.

Problem 2: nh-poly

Statement

Furthermore, all the artifacts were generated with nh_poly=3, so they won't work with other configs.

To-do

We need to:

1. Save the grid metadata somewhere in the generated precomputed drag file.
2. Save the version of Clima models used as well.
3. Check whether all grid metadata match before loading the precomputed drag.
4. Create a repository/database of precomputed drag to reduce pre-computation overhead.