Doxygen CI: Warnings as Error

[ax3l]

Make sure that no Doxygen warnings get in, as we do in other CI runs already.

Depends on AMReX-Codes/amrex#3061

[dpgrote]

Thanks!

[EZoni]

Found this old PR and just merged development in to see if we can finalize it easily.

[EZoni]

FYI, still struggling to "fix" this:

/home/runner/work/WarpX/WarpX/Source/Utils/ParticleUtils.H:36: error: no matching file member found for 
amrex::DenseBins< ParticleTileDataType > ParticleUtils::findParticlesInEachCell(int lev, const amrex::MFIter &mfi, WarpXParticleContainer::ParticleTileType &ptile)
Possible candidates:
 'amrex::DenseBins< ParticleTileDataType > findParticlesInEachCell(int lev, const amrex::MFIter &mfi, ParticleTileType &ptile)' at line 40 of file /home/runner/work/WarpX/WarpX/Source/Utils/ParticleUtils.cpp
 (warning treated as error, aborting now)

[EZoni]

I'd be happy to finalize this, unfortunately when I tried in December I ran into the weird "error" (which seems to me like a false positive) described in #3560 (comment) above, and I could not figure out how to fix it. We can see how it goes now, after the latest rebase.

[ax3l]

We could try to check if the .H and .cpp use the same namespace::prefixes:: for their types in arguments and that the include of the .H file is in the respective .cpp file. I see something similar in the implicit solver.