Split the register/unregister functions into an rmw and hazcat component

[nightduck]

hazcat/hazcat/include/hazcat/hazcat_message_queue.h

Lines 45 to 57 in 21f2823

	// Registers a publisher with the zero copy buffer associated with it's name. If none exists, one
	// is created. If an existing one does not accommodate the memory domain or history requirements of
	// the publisher, it will be resized. Messages will not be able to be published or taken while
	// this resize operation is taking place
	rmw_ret_t
	hazcat_register_publisher(rmw_publisher_t * pub);
	// Registers a subscription with the zero copy buffer associated with it's name. If none exists, one
	// is created. If an existing one does not accommodate the memory domain or history requirements of
	// the subscription, it will be resized. Messages will not be able to be published or taken while
	// this resize operation is taking place
	rmw_ret_t
	hazcat_register_subscription(rmw_subscription_t * sub);

hazcat/hazcat/include/hazcat/hazcat_message_queue.h

Lines 68 to 72 in 21f2823

	rmw_ret_t
	hazcat_unregister_publisher(rmw_publisher_t * pub);
	rmw_ret_t
	hazcat_unregister_subscription(rmw_subscription_t * sub);

The rmw should call this function by passing the internal data element only (pub_sub_data_t), eliminating hazcat's need for linking rmw libraries.