fluids: Make ProblemData a pointer to struct

We basically use it as a pointer-to-struct type everywhere, so might as
well make it consistent with everything else

Merge pull request #1537 from CEED/jeremy/pragma-once

Use #pragma once for non-JiT headers

minor - update copyright headers

Merge pull request #1529 from CEED/jrwrigh/fix_multiplicity_training

fluids: Fix SmartSim training multiplicity, add GetInverseMultiplicity

fluids: Add GetInverseMultiplicity

Merge pull request #1517 from CEED/jrwrigh/ratel_sync

fluids: Sync with Ratel changes

fluids: Sync with Ratel, get ceed-utils.h

Merge pull request #1361 from CEED/jrwrigh/external_sgs

fluids: Add external SGS DD inference capability

fluids: Implement sequential SGS DD eval

fluids: Refactor function names

- PascalCase for acronyms longer than 2 letters
- Remove the "Anisotropic" qualifier from function names, as we only
have one data-driven SGS model. If we add an is

fluids: Refactor function names

- PascalCase for acronyms longer than 2 letters
- Remove the "Anisotropic" qualifier from function names, as we only
have one data-driven SGS model. If we add an isotropic model later, we
can give that the "Isotropic" qualifier on it's function names
- Remove the "Model" qualifier from function names. "SgsDD" is
communicative enough (Subgrid-stress inherently means a model)

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fluids: Change SGS IFunctionApply to use NewtonianIdealGasContext

- It doesn't need anything more than that

fluids: Create generic SGS DD eval interface

- Existing implementation now called "Fused" evaluation

fluids: Add missing OperatorApplyContextDestroy's

Merge pull request #1203 from CEED/jrwrigh/smartsim

fluids: SmartSim Online Data-Driven SGS training

fluids: Agnosticize VeloGradient projection setup

- It can now setup more than just user->grad_velo_proj

Merge pull request #1381 from CEED/jrwrigh/fixup_coords

fluids: Remove coordinates from IFunction_NodalSgs

fluids: Remove coordinates from IFunction_NodalSgs

- Stragler from previous PR

interface - rename CEED_BASIS_COLLOCATED to CEED_BASIS_NONE

Merge pull request #1309 from CEED/jrwrigh/elem_restr_refactor

fluids: Add DMPlexCeedElemRestriction*Create

fluids: Add DMPlexCeedElemRestriction*Create

Replaces CreateRestrictionFromPlex and GetRestrictionForDomain

Merge pull request #1259 from CEED/jrwrigh/fluids-cleanup

fluids: Misc cleanup

fluids: Correct PetscFunction{Return,BeginUser} placement

- Respect the PETSc standard for style (https://petsc.org/release/developers/style/#coding-conventions-and-style)

fluids: Make function names in consistent format

- Mainly remove `_` and acronymns with more than 2 letters should
respect CamelCase (ie. `StgFunction` not `STGFunction`)

Merge pull request #1308 from CEED/jrwrigh/setup_fem

Fluids: Add DMSetupByOrder helper functions

fluids: Add DMSetupByOrder_* helper function