Object CreaPrim: adress the Scene Update error, fixes

Bumped version to 0.3.11
Part of the T51547:
Solve the crash with the scene update check if there is
no active context object
Pep8 cleanup
Replace tabs with spaces
Rename the scene properties to Creaprim_Apply and Creaprim_Name
Cleanup the generated code
Add a check for existence of Polygons in the mesh data -
if they don't exist the generated code will fail