Add z_top to clm artifacts and rename

[imreddyTeja]

See accompanying ClimaLand PR

Adds Canopy height to both clm data artifacts as z_top.

The MONTHLY_MEAN_TOP is a 4D variable on Lon, lat, time, and pft.
The dominant pft is taken, and time is averaged across the months. Averaging the time
is equivalent to just selecting a time, because even though there is a time dim, there is no variance across time

In the 0.125x0.125 surface data file, the MONTHLY_MEAN_TOP is zero everywhere. Because of this,
when creating the 0.125x0.125 pft data, the script uses the closest lon and lat from MONTHLY_MEAN_TOP in the 0.9x1.25 surface data file to calculate z_top (still uses dominant PFT from 0.125x0.125 surface data file).

0.9x1.25

0.125x0.125

Also rename the low res artifact from clm_data
to clm_data_0.9x1.25 and the high res artifact from
clm_data_0.125 to clm_data_0.125x0.125

Checklist:

• I created a new folder $artifact_name
  • I added a README.md in that that folder that
    • describes the data and processing done to it
    • lists the sources of the raw data
    • lists the required citation, licenses
  • If applicable (e.g., for Creative Commons), I added a LICENSE file
  • I added the scripts that retrieve, process, and produce the artifact
  • I added the environment used for such scripts (typically, Project.toml
    and Manifest.toml)
  • I added the OutputArtifacts.toml file containing the information
    needed for package developers to add $artifact_name to their package
• I uploaded the artifact folder to the Caltech cluster (in
  /groups/esm/ClimaArtifacts/artifacts/$artifact_name)
• I added the relevant code to the Overides.toml on the Caltech Cluster
  (in /groups/esm/ClimaArtifacts/artifacts/Overrides.toml)
• I added a link to the main README.md to point to the new artifact