Add Milan Support to remap_restarts

[mathomp4]

At the moment, remap_restarts doesn't know about SLES15 or the Milan nodes. This is doable but we'll have to rely on CMake to alter the code like we do in gcm_setup (since we know at build time where something was built, we can then change the "allowed" constraints).

I can work with @weiyuan-jiang on this.

[atrayano]

Most of the issues there are related to the SBATCH syntax. The important changes are the 'qos' is not supported, and --ntaska has to be replaced with --nodes and --ntasks-per-node. Also I had to do --partition=scutest

I already made changes and committed them on a brach: bugfix/atrayano/fixes_for_milan

This branch is not meant to be a PR. These are changes I made to get quicky my regridded restarts. The changes need to be done a lot more carefully, to distinguish discover vs discover-mil, and to make sure the scripts work on both systems

[weiyuan-jiang]

Thanks @atrayano

[gmao-rreichle]

addressed in #43