New Octane Rule: `no-actions-hash`

Pulled from https://github.com/ember-cli/eslint-plugin-ember/issues/533 which proposes a new set of rules for Octane related best practices

Disallow using the actions hash, favoring the @action decorator or foo: action(function() {})) instead

### Good
export default Component.extend({
  foo: action(function() {}))
});

export default class MyComponent extends Component {
  @action
  foo {}
}

### Bad
export default Component.extend({
  actions: {
    ...
  }
});

export default class MyComponent extends Component {
  actions = {
    ...
  }
}

If anyone would like to implement this please comment and work away.

[patocallaghan]

@bmish could you assign this issue to @laurmurclar please?

[laurmurclar]

I will happily take this one 👋