Add missing object functions to analog inputs and values (#568)

* ai.c: add possibility to set a custom object name

The Name_Set function is already declared in the header but not
implemented. With this implementation, one can set a custom object name
from a server application.

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>

* av.c: add possibility to set a custom object name

The Name_Set function is already declared in the header but not
implemented. With this implementation, one can set a custom object name
from a server application.

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>

* ai.c: implement function to set custom description

For now the hard-coded behaviour was to return the object name whenever
a client requested the value for the description.

Therefore implement the functions Description and Description_Set already
declared in the header and add a Description property to the data
structure used. We also need to properly implement PROP_DESCRIPTION in
the Read_Property function.

This way we can set and read a custom decsription from a server application
and send the appropriate response to a read-property request asking for
PROP_DESCRIPTION.

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>

* av.c: implement function to set custom description

For now the hard-coded behaviour was to return the object name whenever
a client requested the value for the description.

Therefore implement the functions Description and Description_Set already
declared in the header and add a Description property to the data
structure used. We also need to properly implement PROP_DESCRIPTION in
the Read_Property function.

This way we can set and read a custom decsription from a server application
and send the appropriate response to a read-property request asking for
PROP_DESCRIPTION.

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>

* ai.c: implement function to set custom units

Implement the object functions related to Units already declared in the
header.

By default Analog Inputs will have the Unit UNITS_PERCENT. Add
functionality to be able to set and read custom units from a server
application.

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>

* av.c: implement function to set custom units

Implement the object functions related to Units already declared in the
header.

By default Analog Values will have the Unit UNITS_NO_UNIT. Add
functionality to be able to set and read custom units from a server
application.

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>

---------

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>
Co-authored-by: Sebastian Weyer <sebastian.weyer@smile.fr>

src/bacnet/basic/object/av.h

@@ -52,6 +52,8 @@ extern "C" {
         float Prior_Value;
         float COV_Increment;
         bool Changed;
+        char* Object_Name;
+        char* Description;
 #if defined(INTRINSIC_REPORTING)
         uint32_t Time_Delay;
         uint32_t Notification_Class;