Fixes the CreateObject service list-of-initial-values encoding and decoding by refactoring the data structure to be similar to WriteProperty. The implementation changes from using a linked list of property values to using a flat buffer approach with delayed decoding.
Changes:
* Refactored BACNET_CREATE_OBJECT_DATA structure to use an application_data buffer instead of a linked list for initial values
* Added a new create_object_process() and create_object_initializer_list_process() functions to centralize object creation logic and error reporting
* Updated all device implementations to use the new centralized creation functions
* Enhanced the create-object example application to support command-line specification of initial property values
* Added comprehensive test coverage for the new encoding/decoding and processing functions
* Converted device object test to use common read-write property test. Extended the basic BACnet device object example API.
* Created BACnet/IP and COV test mocks to enable device object testing with less dependencies.