Move `read_partitioned_msh` to BcubeGmsh

[bmxam]

Move https://github.com/bcube-project/BcubeMPI.jl/blob/a629c1d9f60fecc29634636766fbd4ad1fdcd0d4/src/mesh/gmsh_utils.jl#L19 to BcubeGmsh. We just have to change the comm attribute to a rank attribute and there is no more dependency to MPI. As for the returned argument, it could be a Mesh and ghost_tag2part.