feat(nodes): use ItemStorageABC for tensors and conditioning

Turns out `ItemStorageABC` was almost identical to `PickleStorageBase`. Instead of maintaining separate classes, we can use `ItemStorageABC` for both.

There's only one change needed - the `ItemStorageABC.set` method must return the newly stored item's ID. This allows us to let the service handle the responsibility of naming the item, but still create the requisite output objects during node execution.

The naming implementation is improved here. It extracts the name of the generic and appends a UUID to that string when saving items.

invokeai/app/services/invocation_services.py

@@ -29,7 +29,6 @@ if TYPE_CHECKING:
     from .model_manager.model_manager_base import ModelManagerServiceBase
     from .model_records import ModelRecordServiceBase
     from .names.names_base import NameServiceBase
-    from .pickle_storage.pickle_storage_base import PickleStorageBase
     from .session_processor.session_processor_base import SessionProcessorBase
     from .session_queue.session_queue_base import SessionQueueBase
     from .shared.graph import GraphExecutionState
@@ -66,8 +65,8 @@ class InvocationServices:
         names: "NameServiceBase",
         urls: "UrlServiceBase",
         workflow_records: "WorkflowRecordsStorageBase",
-        tensors: "PickleStorageBase[torch.Tensor]",
-        conditioning: "PickleStorageBase[ConditioningFieldData]",
+        tensors: "ItemStorageABC[torch.Tensor]",
+        conditioning: "ItemStorageABC[ConditioningFieldData]",
     ):
         self.board_images = board_images
         self.board_image_records = board_image_records