Tidy names and locations of modules

- Rename old "model_management" directory to "model_management_OLD" in order to catch
  dangling references to original model manager.
- Caught and fixed most dangling references (still checking)
- Rename lora, textual_inversion and model_patcher modules
- Introduce a RawModel base class to simplfy the Union returned by the
  model loaders.
- Tidy up the model manager 2-related tests. Add useful fixtures, and
  a finalizer to the queue and installer fixtures that will stop the
  services and release threads.

tests/backend/model_manager/model_loading/test_model_load.py

@@ -0,0 +1,21 @@
+"""
+Test model loading
+"""
+
+from pathlib import Path
+
+from invokeai.app.services.model_install import ModelInstallServiceBase
+from invokeai.app.services.model_load import ModelLoadServiceBase
+from invokeai.backend.textual_inversion import TextualInversionModelRaw
+from tests.backend.model_manager.model_manager_fixtures import *  # noqa F403
+
+def test_loading(mm2_installer: ModelInstallServiceBase, mm2_loader: ModelLoadServiceBase, embedding_file: Path):
+    store = mm2_installer.record_store
+    matches = store.search_by_attr(model_name="test_embedding")
+    assert len(matches) == 0
+    key = mm2_installer.register_path(embedding_file)
+    loaded_model = mm2_loader.load_model_by_config(store.get_model(key))
+    assert loaded_model is not None
+    assert loaded_model.config.key == key
+    with loaded_model as model:
+        assert isinstance(model, TextualInversionModelRaw)