Added Default network create API
Added Default network create API

This Api can be used by the upcoming External access functionality to
create default network and any additional network for its operation

Signed-off-by: Madhu Venugopal <d22477479bbf55ba62bd822f4112c80f292c7805@socketplane.io>

socketplane/socketplane,mrjana/socketplane,mrjana/socketplane,socketplane/socketplane,socketplane/socketplane,mrjana/socketplane