Fix driver/config restructure bug

[pcarruscag]

Proposed Changes

@rsanfer , @talbring please keep the testcases up to date with the new options you are introducing, avoidable bugs are starting to pass...

PR Checklist

• I am submitting my contribution to the develop branch.
• My contribution generates no new compiler warnings (try with the '-Wall -Wextra -Wno-unused-parameter -Wno-empty-body' compiler flags).
• My contribution is commented and consistent with SU2 style.
• I have added a test case that demonstrates my contribution, if necessary.

[talbring]

@pcarruscag I would not call that an avoidable bug considering the fact that the regression test passed.

[pcarruscag]

It passed because the config options were not updated and so no mesh deformation was specified for any of the FSI cases.

[talbring]

If this has no influence on the test values then we should change these cases I would say.

[economon]

Let’s try to keep it positive here.. @talbring has an interesting point that the tests should show some sensitivity to major changes like the grid deformation not being specified. Can they be made more sensitive to this?

[pcarruscag]

I agree, but some do pick up those changes, just not all of them.

Anyway, you'll notice I put an assert for the condition that was causing the problem instead of an "mpi error". That is inline with the philosophy that errors/exceptions are to deal with user errors and asserts to help debugging (they are ignored with -DNDEBUG). I can off-course change it.

[rsanfer]

I have just reproduced this error and indeed all static FSI cases fail, so let's merge the bugfix in.
Idea is, replacing FLUID_STRUCTURE_STATIC and FLUID_STRUCTURE with the new mesh solver, so these options should change again soon (and I'll make sure they get properly documented).
Still, I think we should add another steady-state FSI test case, to catch this kind of bugs in the regression tests. Let me do that in the coming PR.