Added Zephyr settings and basic device in subsys. (#697)

* Added Zephyr settings subsys to enable storing of BACnet values according to BACnet object property value path.

* Added BACnet Basic features to enable basic samples. Refactored the zephyr BACnet profile B-SS sample to use BACnet basic subsys.

zephyr/include/bacnet_basic/bacnet_port_ipv4.h

@@ -0,0 +1,31 @@
+/**
+ * @file
+ * @brief API for the BACnet datalink tasks for handling the device specific 
+ *  data link network port layer
+ * @author Steve Karg <skarg@users.sourceforge.net>
+ * @date April 2024
+ * @copyright SPDX-License-Identifier: MIT
+ */
+#ifndef BACNET_PORT_IPV4_H
+#define BACNET_PORT_IPV4_H
+
+#include <stdbool.h>
+#include <stdint.h>
+/* BACnet Stack defines - first */
+#include "bacnet/bacdef.h"
+#include "bacnet/datalink/bvlc.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+void bacnet_port_ipv4_foreign_device_init(
+    const uint16_t ttl_seconds,
+    const BACNET_IP_ADDRESS *bbmd_address);
+void bacnet_port_ipv4_task(uint16_t elapsed_seconds);
+bool bacnet_port_ipv4_init(void);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif