Proposal: add `qmlloader` fixture

Hi I created this nice fixture and wanted to ask if it would be usefull to contribute it here?
It supports loading QML from strings or from file and retrieving the loaded item with ease.

T = TypeVar("T")

@define(slots=False)
class QmlTestCase:
    bot: QtBot
    engine: QQmlApplicationEngine = field(factory=QQmlApplicationEngine)

    def __attrs_post_init__(self):
        main = Path(__file__).parent / "qmltester.qml"
        self.engine.load(main.resolve(True))

    @property
    def _loader(self) -> QQuickItem:
        self.root = self.engine.rootObjects()[0]
        return self.root.findChild(QQuickItem, "contentloader")

    def load(self, path: Path) -> QQuickItem:
        self.bot.wait(100)
        self._loader.setProperty("source", str(path.resolve(True)))
        return self._loader.property("item")

    def loads(self, content: str) -> QQuickItem:
        self.comp = QQmlComponent(self.engine)
        self.comp.setData(content.encode("utf-8"), QUrl())
        self._loader.setProperty("source", "")
        self._loader.setProperty("sourceComponent", self.comp)
        return self._loader.property("item")

    def find(self, objectname: str, type: T = QQuickItem) -> T:
        return self.window.findChild(type, objectname)


@pytest.fixture()
def qmlloader(qtbot):
    return QmlTestCase(qtbot)

Usage:

@pytest.mark.parametrize("status", iter(object_with_enum.Status))
def test_accessible_from_qml(qmlloader, status):
    qml = (
        """
import QtQuick
import QtGql 1.0 as GQL

Rectangle {
    property int enumValue: GQL.Enums.%s
}
"""
        % status.name
    )

    EnumTestCase.compile()
    item = qmlloader.loads(qml)
    assert item.property("enumValue") == status.value

Start with the proposed QmlTestCase and qmlloader fixture, then inspect qmltester.qml and the example test_accessible_from_qml usage to determine where this fixture would belong. Confirm the supported load, loads, and find behavior and agree on the project’s expected tests and API before implementing; done means the contribution is accepted with those behaviors covered.