Use marshalling for function calls

[thekid]

Example

use com\mongodb\{Collection, ObjectId};
use com\openai\tools\Functions;

$conn= ...
$users= $conn->collection('database', 'users');

$functions= (new Functions())->register('testing', new class($users) {
  public function __construct(private Collection $users) { }

  public function user(ObjectId $id) {
    return $this->users->find($id)->first();
  }
});

$result= $functions->calls()->call('testing_user', '{"id": "507f1f77bcf86cd799439011"}');

The LLM will pass a user ID per string to the function, which will unmarshal it to an ObjectId. The returned Document will be marshalled to its properties, and yielded as a JSON object.

[thekid]

Released in https://github.com/xp-forge/openai/releases/tag/v0.5.0