Function definePolicy

definePolicy(
    authorize: (
        dependencies: any,
    ) => (event: IncomingEvent) => boolean | Promise<boolean>,
): (dependencies: any) => IPolicy
The imperative counterpart of a policy class: a plain function.

It receives the same dependencies a class would get through its constructor.
Parameters
- authorize: (dependencies: any) => (event: IncomingEvent) => boolean | Promise<boolean>
  Decides whether the caller may proceed.
Returns (dependencies: any) => IPolicy
A factory producing a policy.
Example
```
export const updatePostPolicy = definePolicy(({ posts }) => async (event) => {
  const post = await posts.find(event.get('id'))
  return post.authorId === event.getMetadataValue('auth')?.sub
})
```