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.

invokeai/backend/ip_adapter/ip_adapter.py

@@ -10,6 +10,7 @@ from transformers import CLIPImageProcessor, CLIPVisionModelWithProjection
 from invokeai.backend.ip_adapter.ip_attention_weights import IPAttentionWeights
 
 from .resampler import Resampler
+from ..raw_model import RawModel
 
 
 class ImageProjModel(torch.nn.Module):
@@ -91,7 +92,7 @@ class MLPProjModel(torch.nn.Module):
         return clip_extra_context_tokens
 
 
-class IPAdapter:
+class IPAdapter(RawModel):
     """IP-Adapter: https://arxiv.org/pdf/2308.06721.pdf"""
 
     def __init__(