Read From Mesh vs Mesh Generation Disparity

[eyoung55]

There is a slight disparity between the lift/drag results generated by two different approaches: (1) when running the flag2d result in "build mesh" mode and (2) when setting input_mesh_dir: Trueand using the mesh directory output from the solve/approach (1).

Steps to reproduce:

1. run flag2d.yaml for 20 steps with no other modifications
2. locate the mesh directory output from step 1
3. re-run the flag2d.yaml for 20 steps with --general.input_mesh_dir=path/to/mesh/dir
4. compare lift_and_drag.csv from (1) and (3)