Fix: disallow extra properties in rule options

[andreww2012]

Plugin rules currently allow extra properties to be passed in options object in certain places, which should not be allowed. This makes it easier for typos in rule options to go unnoticed.

This PR simply disallows extra properties in rules' schemas which currently allow them.

[mozfreddyb]

Can you write tests that lead to failures when additional properties are supplied?

[andreww2012]

I'm not sure how one would write such tests using RuleTester, but I think they aren't necessary, because this is the internal ESLint behavior that always throws an error if supplied options do not satisfy the rule's JSON schema, and I would imagine that was not expected to be tested by plugin authors. There exist a lot of ESLint plugins and I believe no ones is testing that behavior.

[mozfreddyb]

I'm not super enthusiastic about a pull request that is not testable. Can anyone else think of something?