feat(nodes): add control adapter processed images to metadata

In the client, a controlnet or t2i adapter has two images:
- The source control image: the image the user selected (required)
- The processed control image: the user's image after we've processed it (optional)

The processed image is optional because a user may provide a pre-processed image.

We only actually use one of these images when building the graph, and until this change, we only stored one of the in image metadata. This created a situation where only a processed image was stored in metadata - say, a canny edge map - and the user-selected image wasn't provided.

By adding the processed image to metadata, we can recall both the control image and optional processed image.

This commit is followed by a UI-facing changes to support the change.

Author: psychedelicious

invokeai/app/invocations/metadata.py

@@ -42,18 +42,15 @@ class IPAdapterMetadataField(BaseModel):
     """IP Adapter Field, minus the CLIP Vision Encoder model"""
 
     image: ImageField = Field(description="The IP-Adapter image prompt.")
-    ip_adapter_model: ModelIdentifierField = Field(
-        description="The IP-Adapter model.",
-    )
-    weight: Union[float, list[float]] = Field(
-        description="The weight given to the IP-Adapter",
-    )
+    ip_adapter_model: ModelIdentifierField = Field(description="The IP-Adapter model.")
+    weight: Union[float, list[float]] = Field(description="The weight given to the IP-Adapter")
     begin_step_percent: float = Field(description="When the IP-Adapter is first applied (% of total steps)")
     end_step_percent: float = Field(description="When the IP-Adapter is last applied (% of total steps)")
 
 
 class T2IAdapterMetadataField(BaseModel):
-    image: ImageField = Field(description="The T2I-Adapter image prompt.")
+    image: ImageField = Field(description="The control image.")
+    processed_image: Optional[ImageField] = Field(default=None, description="The control image, after processing.")
     t2i_adapter_model: ModelIdentifierField = Field(description="The T2I-Adapter model to use.")
     weight: Union[float, list[float]] = Field(default=1, description="The weight given to the T2I-Adapter")
     begin_step_percent: float = Field(
@@ -67,6 +64,7 @@ class T2IAdapterMetadataField(BaseModel):
 
 class ControlNetMetadataField(BaseModel):
     image: ImageField = Field(description="The control image")
+    processed_image: Optional[ImageField] = Field(default=None, description="The control image, after processing.")
     control_model: ModelIdentifierField = Field(description="The ControlNet model to use")
     control_weight: Union[float, list[float]] = Field(default=1, description="The weight given to the ControlNet")
     begin_step_percent: float = Field(