Tighten solver tolerances for terrain reg test on GPU

[marchdf]

Summary

To avoid reg test non-determinism when running on GPU, it's good to have tight tolerances for the linear solvers. Also fixed a bunch of whitespace weirdness.

GPU Run-to-run variability before this PR:

            variable name            absolute error            relative error
                                        (||A - B||)         (||A - B||/||A||)
 ----------------------------------------------------------------------------
 level = 0
 density                                          0                         0
 mu_turb                            1.199741639e-08           6.670257731e-10
 temperature                        2.304420832e-08           7.419106396e-11
 temperature_mueff                  3.599225096e-08           6.670256295e-10
 terrain_height                                   0                         0
 terrainz0                                        0                         0
 velocityx                          7.774811905e-10           7.154064139e-11
 velocityy                          1.340445602e-10           1.462027369e-10
 velocityz                          2.579388092e-10           4.365218156e-10
 velocity_mueff                     1.199741639e-08           6.670254023e-10
 terrain_blank                                    0                         0
 terrain_drag                                     0                         0

After:

            variable name            absolute error            relative error
                                        (||A - B||)         (||A - B||/||A||)
 ----------------------------------------------------------------------------
 level = 0
 density                                          0                         0
 mu_turb                            1.434971031e-10           7.978081558e-12
 temperature                         3.97903932e-13           1.281055768e-15
 temperature_mueff                  4.304914203e-10           7.978081503e-12
 terrain_height                                   0                         0
 terrainz0                                        0                         0
 velocityx                          2.060573934e-12           1.896056184e-13
 velocityy                          3.194278175e-12           3.484030062e-12
 velocityz                          2.683495787e-13           4.541426202e-13
 velocity_mueff                     1.434971031e-10           7.978077122e-12
 terrain_blank                                    0                         0
 terrain_drag                                     0                         0

Pull request type

Please check the type of change introduced:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe): reg test update

Checklist

This PR was tested by running:

• the unit tests
  • on GPU
  • on CPU
• the regression tests
  • on GPU
  • on CPU