USER-DPD another zero compute optimization

This relates to commit 4eb08a58 that was applied to pair_dpd_fdt_energy

Added source code and documentation for USER-CGDNA

USER-DPD: Skip a0*stuff computations, if a0 was set to zero in pair_coeff

USER-DPD: bugfix for a segfault when using MOLECULE and DPD together.

This saves around 10% of the runtime for many of our tests using SSA.

Fixes for srp example

Neighbor fixes

Bugfix in the fix_ipi initialization - prevents multiple open_socket calls

Make fix_qeq_reax_kokkos request its own neighbor list

Make fix_rx request its own neighbor list

Updated the reference for the flow/gauss method

Coord atom orientorder atom enhancements

USER-DPD: fix a typo in the DPD-H example input; update reference output.

Collected small bugfixes

print the last input line, when error->all() is called

Updating Kokkos lib

Updated images of succesful merge.

rather than adjusting the communication cutoff, we just print out the minimum value needed and error out

i suspect, this communication cutoff adjustment was included into the code before it was possible to separately set it via comm_modify. stopping with an error message printing the needed/current value is cleaner, in keeping with other modules in LAMMPS and much less problematic.

Included a flag to prevent multiple open_socket calls if run is included multiple times in the LAMMPS input

fix for bug with compute rdf with pair reax/c. we must not copy a neighbor list, if newton settings are not compatible

an alternate route to address this issue would be to allow an "ANY" setting for neighbor list requests and then query the neighbor list for newton setting instead of the force class.

during setup, checking timestep doesn't seem to be sufficient. comparing bins and stencil point, too.

in addition, relevant pointers were not properly initialized to NULL