Add Tests for Stateful Event Handling and Inventory Module

[vikman90]

Related issue
Closes #413

Description

This PR introduces new tests to enhance the reliability of stateful event handling and the SendDataEvent method in the Inventory module. These tests ensure correct behavior when processing deletion events and handling empty data objects in the Queue.

These changes address the testing gap identified in the implementation of PR #393, which modified the behavior of stateful events to exclude the event body for delete operations.

Changes Included

1. Queue Message Handling
   • Added a test to verify that when a message with an empty object ({}) as data is dequeued, the body only includes metadata.
2. Inventory Module
   • Introduced a basic unit test for the SendDataEvent method.
   • Added a test for the specific case when operation is delete.

Testing

• All new tests pass and confirm the expected behavior.
• Existing tests remain unaffected, ensuring backward compatibility.

[cborla]

LGTM!