Set HYPRE_HAVE_MPI_COMM_F2C in CMake build

[Yannicked]

In the CMake build, the HYPRE_HAVE_MPI_COMM_F2C variable was not set, which causes invalid communicators in some MPI implementations when HYPRE was called from Fortran.

This pull request addresses the issue by using CMake's check_symbol_exists to determine if the function or macro is available, and sets the variable accordingly.