Update python coupling

Closes #153 and #162

See merge request walberla/walberla!495

Adapt to get_headers function from pystencil

See merge request walberla/walberla!497

add clang 11 to CI

See merge request !496

Clean CUDA communication module

See merge request !492

Update !487 and avoid implicit OpenMP parallelization in mesh::BoundarySetup

See merge request !493

Assign flags to imported mesh geometries without a boundary handling

See merge request walberla/walberla!487

New hash algorithm for Cell and Vector<int> objects

Closes #160

See merge request !482

Add assertion for adding multiple Sweeps to a single SweepAdder object

See merge request !486

pin lbmpy to specific version

See merge request walberla/walberla!490

increase cmake minimum Version to 3.14

See merge request !485

GPU Communication Block Selectors

See merge request !488

Fix: Fluctuating LBM

See merge request !489

recent versions of cmake warn if the argument is not the same as the FindXXX.cmake name

See merge request !483

Update new lbmpy version

See merge request !481

add Intel OneApi compiler to CI

See merge request !465

Revert !146: remove Su viscoelasticity

Closes #158

See merge request !480

Documentation maintenance

See merge request walberla/walberla!479

remove allow-run-as-root in MPIEXEC_PREFLAGS it is handled via the environment variables in the docker images
check for intelclang or clang before checking for OpenMP bug

Delete Doxygen blocks duplicated in both .h and .cpp files.
Fix incorrect argument names in \param blocks. Fix filenames
in \file blocks. Fix broken Doxygen syntax (broken numerated
lists containing more than 9 items, invalid HTML tags, broken
links in \ref and malformed math equations). Wrap code blocks
inside \code ... \endcode.