Add tests for container-based problems (only simulation)

[ffelten]

Description

Adding some automated tests for container-based problems--only simulation since they're pretty heavy.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

Checklist:

• I have run the pre-commit checks with pre-commit run --all-files
• I have run ruff check . and ruff format
• I have run mypy .
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• [ x I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[g-braeunlich]

LGTM

[ffelten]

@cashend seems like we specify only one objective in the airfoil metdata (cd). In practice, simulate and optimize return two (cl also I guess). Should we change the metadata or not return cl ?