[Modules] Specific modulepath labels

[Xavier D. <xav...@gm...>]

Dear All,

A new modulefile command named modulepath-label is introduced for next
version (5.4).

modulepath-label command defines a label to use to designate
modulepath in module avail output. This new command should be used in
global or modulepath-specific rc files.

See example at https://modules.readthedocs.io/en/latest/MIGRATING.html#specific-modulepath-labels

Regards,
Xavier