Change the handling of LabelWhiteList config option to use a pointer to
detect when the option is unset. This doesn't fix any detected crash but
is merely general improvement and stabilization, serving easier testing.
Also, use the regexp type from the core libs for the config struct -
dropping the unmasrhalling code for our custom regexp type - as the core
regexp now implements unmarshaller itself.
This PR adds a config option for setting the NFD API controller resync period.
The resync period is only activated when the NodeFeature API has been
enabled (with -enable-nodefeature-api).
Signed-off-by: AhmedGrati <ahmedgrati1999@gmail.com>
