Revert "replace KwargsNode with TypedDict"

This reverts commit 6e2ed71.

bioimageio/spec/_internal/base_nodes.py

@@ -382,6 +382,20 @@ def _serialize(self) -> str:
         return self.data
 
 
+class KwargsNode(Node):
+    def get(self, item: str, default: Any = None) -> Any:
+        return self[item] if item in self else default
+
+    def __getitem__(self, item: str) -> Any:
+        if item in self.model_fields:
+            return getattr(self, item)
+        else:
+            raise KeyError(item)
+
+    def __contains__(self, item: str) -> int:
+        return item in self.model_fields
+
+
 class FileDescr(Node):
     source: FileSource
     """∈📦 file source"""

bioimageio/spec/model/v0_4.py

@@ -26,7 +26,7 @@
     field_validator,
     model_validator,
 )
-from typing_extensions import Annotated, LiteralString, Self, TypedDict, assert_never
+from typing_extensions import Annotated, LiteralString, Self, assert_never
 
 from bioimageio.spec._internal.base_nodes import FileDescr as FileDescr
 from bioimageio.spec._internal.base_nodes import KwargsNode, Node, NodeWithExplicitlySetFields, StringNode
@@ -391,7 +391,7 @@ class TensorDescrBase(Node):
     If not specified, the full data range that can be expressed in `data_type` is allowed."""
 
 
-class ProcessingKwargs(TypedDict):
+class ProcessingKwargs(KwargsNode):
     """base class for pre-/postprocessing key word arguments"""