{LYN-4372} fix for Python exit crash (#1600)

There is a crash when sys.exit() was being called since embedded Python
should not have control of the application lifetime. The Py_InspectFlag
puts the Python VM into 'inspection mode' which prevents the app
shutdown when any sys.exit() is invoked.

Notes:
* skips 'regset' extra command line in PythonBindingsExample
* added methods for handling PythonBindingsExample errors

Test: added Application_SystemExit_Blocked and
fixed up Application_Run_Fails now is Application_Run_Works

Gems/EditorPythonBindings/Code/Source/PythonSystemComponent.cpp

@@ -496,6 +496,7 @@ namespace EditorPythonBindings
             // ignore system location for sites site-packages
             Py_IsolatedFlag = 1; // -I - Also sets Py_NoUserSiteDirectory.  If removed PyNoUserSiteDirectory should be set.
             Py_IgnoreEnvironmentFlag = 1; // -E
+            Py_InspectFlag = 1; // unhandled SystemExit will terminate the process unless Py_InspectFlag is set
 
             const bool initializeSignalHandlers = true;
             pybind11::initialize_interpreter(initializeSignalHandlers);