Add option `builder` to `@limit` to apply an actual `LIMIT` clause

[spawnia]

• [x] Added or updated tests
• [x] Documented user facing changes
• [x] Updated CHANGELOG.md

Changes

If your field is resolved through a database query, you may add the builder argument to apply an actual LIMIT clause to your SQL:

type Query {
  users(limit: Int @limit(builder: true)): [User!]! @all
}

Breaking changes

None, the default behaviour is the same.