Remove MPI_COMM_WORLD references

[jorblancoa]

The main communicator should be received as parameter from the simulator.

A good place would be to add an extra parameter in the sonata_setup_communicators(MPI_Comm main_comm) method

libsonatareport/src/library/reports.cpp

Line 69 in 77d5d92

void sonata_setup_communicators() {

CoreNEURON and py-neurodamus core submodule would need to be adapted also:
https://github.com/BlueBrain/CoreNeuron/blob/d0cf5503f1f41fb7d313722e800e306a596bd3b3/coreneuron/io/reports/nrnreport.cpp#L63
https://bbpgitlab.epfl.ch/hpc/sim/neurodamus-core/-/blob/main/mod/SonataReportHelper.mod#L86