build,core: add a "main.migrate-ifcfg-rh" configuration option
Summary
This MR adds a new main.migrate-ifcfg-rh
option. When enabled, profiles in ifcfg-rh format are automatically converted to keyfile at startup.
Purpose
The ifcfg-rh plugin is deprecated and in maintenance-mode only and we plan to drop it in the future.
To do that, we need to make sure nobody has profiles in ifcfg format. This option will help with that. For example, we proposed to enable this automatic migration on Fedora:
https://fedoraproject.org/wiki/Changes/MigrateIfcfgToKeyfile