HPCX and IMPI modules not compatible with Lmod

[xpillons]

Lmod is failing to load HPCX and IMPI modules.
Repro :

• yum install Lmod

• module use /usr/share/Modules/modulefiles

• module load mpi/hpcx
  Lmod has detected the following error: The following module(s) are unknown: "/opt/hpcx-v2.7.4-gcc-MLNX_OFED_LINUX-5.2-1.0.4.0-redhat7.8-x86_64/modulefiles/hpcx"

• module load mpi/impi
  Lmod has detected the following error: The following module(s) are unknown: "/opt/intel/impi/2018.4.274/intel64/modulefiles/mpi"

[hmeiland]

Looks like a recursive load of another module outside of modulepath is causing issues; either copy original module to modulepath or create symlinks could solve this...

[hmeiland]

proposal #102 made for CentOS 7.9; if ok, I'll update other dists/versions...

[hmeiland]

added moving from environment-modules to Lmod in PR #102; this would break some modules in outside CentOS 7.9; so please allow me to finish the PR before accepting....