How to safely rename policy rules

[lcarva]

In #793, the policy rule test.required_tests_passed is renamed to test.no_failed_tests.

This can have implications for users who explicitly include or exclude that rule. Let's come up with a mechanism that allows us to do this sort of operations in a more robust manner.

[lcarva]

Maybe introduce the concept of an alias?

[zregvart]

In addition to aliasing I think we would need a mechanism to inform folk they need to make a change on their end, i.e. marking a rule as deprecated with a removal dedline.