Refactor/cov subscriptions encoding decoding test (#1296)

* Add BACnetRecipientProcess type encoding and decoding functions with associated tests

* Refactor COV subscription encoding and decoding functions to reduce code size and reuse existing unit tested functions.

* Refactor COV subscription handling to simplify error checking

test/bacnet/basic/object/test/bip_mock.c

@@ -10,14 +10,16 @@
 
 void bip_get_my_address(BACNET_ADDRESS *my_address)
 {
-    (void)my_address;
+    if (my_address) {
+        my_address->mac_len = 0;
+    }
 }
 
 int bip_send_pdu(
     BACNET_ADDRESS *dest,
     BACNET_NPDU_DATA *npdu_data,
     uint8_t *pdu,
-    unsigned pdu_len)
+    uint16_t pdu_len)
 {
     (void)dest;
     (void)npdu_data;

test/bacnet/basic/object/test/device_mock.c

@@ -46,3 +46,57 @@ int Device_Read_Property(BACNET_READ_PROPERTY_DATA *rpdata)
     (void)rpdata;
     return 0;
 }
+
+bool Device_Valid_Object_Id(
+    BACNET_OBJECT_TYPE object_type, uint32_t object_instance)
+{
+    (void)object_type;
+    (void)object_instance;
+    return true;
+}
+
+bool Device_Value_List_Supported(BACNET_OBJECT_TYPE object_type)
+{
+    (void)object_type;
+    return true;
+}
+
+bool Device_COV(BACNET_OBJECT_TYPE object_type, uint32_t object_instance)
+{
+    (void)object_type;
+    (void)object_instance;
+    return false;
+}
+
+void Device_COV_Clear(BACNET_OBJECT_TYPE object_type, uint32_t object_instance)
+{
+    (void)object_type;
+    (void)object_instance;
+}
+
+bool Device_Encode_Value_List(
+    BACNET_OBJECT_TYPE object_type,
+    uint32_t object_instance,
+    BACNET_PROPERTY_VALUE *value_list)
+{
+    (void)object_type;
+    (void)object_instance;
+    (void)value_list;
+    return true;
+}
+
+uint16_t Routed_Device_Object_Index(void)
+{
+    return 0;
+}
+
+bool Set_Routed_Device_Object_Index(uint16_t index)
+{
+    (void)index;
+    return true;
+}
+
+uint16_t Get_Num_Managed_Devices(void)
+{
+    return 1;
+}