Breaking: Support ESM rules

[bmish]

Fixes #157. I recommend we add this to the upcoming v4 release (#120).

This change updates most rules (rules using our util getRuleInfo to read rule create/meta data) to support rules defined using the ES modules syntax as follows:

export default {
  meta: {},
  create(context) {}
};

TODO:

• Add tests for all affected rules.
• Support variables. We've never supported this so I don't think it's essential now. We can follow-up to try to add it later if we want.

  const rule = { meta: {}, create(context) {} }; 
  export default rule;
  

• Support create function as the default export.

[aladdin-add]

we need to resolve the conflicts. :)