Add tests for PruneSingal and ReQueueAfterSingal functionality

- Updated test_package_init.py to include new expected exports for PruneSingal and ReQueueAfterSingal.
- Created test_signals_and_runtime_functions.py to implement comprehensive unit tests for PruneSingal and ReQueueAfterSingal, covering initialization, sending, and error handling.
- Enhanced test coverage for signal handling in the Runtime class, ensuring robust integration with state management operations.

Author: NiveditJain

python-sdk/tests/test_package_init.py

@@ -15,7 +15,7 @@ def test_package_all_imports():
     """Test that __all__ contains all expected exports."""
     from exospherehost import __all__
 
-    expected_exports = ["Runtime", "BaseNode", "StateManager", "TriggerState", "VERSION"]
+    expected_exports = ["Runtime", "BaseNode", "StateManager", "TriggerState", "VERSION", "PruneSingal", "ReQueueAfterSingal"]
 
     for export in expected_exports:
         assert export in __all__, f"{export} should be in __all__"