Mark simulation component template and entity properties as read-only in simulation tests (as they are in actual games).

Thus throw errors if a simulation test tries to alternate the template instead of silently passing tests with wrong values (as happened tests fixed by rP20015).
Remove the two clones from simulation components that were only relevant for that test.
Add test to test the test.

Differential Revision: https://code.wildfiregames.com/D871
Fixes #4759
setup.js and setup_test.js Reviewed By: leper