Filters to take into account simple field aliases

Resolver:

```ts
export const Org = r.table(db.org, {
	fields: {
		id: true,
		name: true,
		operator_id: 'operatorId', // graphql field differs from db table field
	},
})
```

Query:

```gql
query orgs($operator_id: ID) {
	orgs(filter: { operator_id: $operator_id }) {
		id
		name
	}
}
```

Expected: filter works.

Actual result: column "operator_id" does not exist