[libmdb] Add Libmbd to bundle
I followed the Spglib merge as a template.
Let's see if this passes the CI.
I added both non-MPI and MPI modules, with different Cmake flags. The MPI module uses ELSI, which I understand should be included in the MPI build and available to the other modules?
Closes #134 (closed)
Edited by Micael Oliveira