This will be required to preserve platform network configuration in a
cache across boots. Network configuration will be marshaled to YAML and
unmarshaled back.
Changes are pretty simple and most of the code is auto-generated:
replace `stringer` codegen with `enumer` which produces also methods
which convert from string back to enum values.
Added tests to verify YAML marshaling/unmarshaling.
Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>
