passing extra metadata to TriMesh.from_tri_mesh_and_z_values()

[andy-beer]

Also adds unit test

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 83.09%. Comparing base (91b14c5) to head (21a97f5).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #791 +/- ## ========================================== + Coverage 83.07% 83.09% +0.01% ========================================== Files 191 191 Lines 32727 32727 ========================================== + Hits 27187 27193 +6 + Misses 5540 5534 -6 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.