CI: Add tests for generic controller.mod

[cyberrumor]

In commit cec2e30, tests which previously covered controller.mod were refactored to only support controller.bethesda. This was done to ensure new tests were written. It isn't sufficient to separate tests between one controller and another because that wouldn't provide coverage for whatever controllers inherit from controller.mod, as they might override methods.

Add coverage for correct and incorrect usage of all mod.controller do_* commands.

Add coverage for the controller itself, akin to those in test/bethesda/test_controller_instance.py.