Missing @hapi/scope-start enforcement for comments

#### Support plan

* *is this issue currently blocking your project?* (yes/no): no
* *is this issue affecting a production system?* (yes/no): yes

#### Context

* *node version*: any
* *module version with issue*: 6.0.0
* *last module version without issue*: unknown
* *environment* (e.g. node, browser, native): node
* *used with* (e.g. hapi application, another framework, standalone, ...): eslint
* *any other relevant information*:

#### What are you trying to achieve or the steps to reproduce?

Enable standardised linting syntax using the `@hapi/scope-start` rule for comments at the start of a function scope:

```js
const ok = function () {
// This line should create a linter warning

return true;
};
```

#### What was the result you got?

Pass.

#### What result did you expect?

A warning due to missing empty line at start of function, similar to when any statement / expression is there.

As an aside, it would be nice if the generated warning only marks the line that needs to be moved, rather than the full function block.