* Add comments, rename tests, reorder tests
This commit doesn't change or add any logic
* Add test for overriding a cloud block with a backend block
* Add tests showing multiple instances of cloud or backend blocks cause an error
* Add test showing that backend and cloud blocks cannot be in the same terraform block
* Add test case asserting it's not valid to have both cloud and backend blocks across files in a module
* Clarify comments and replace some comments with test names
* Replace comments with test names
