Fix expected field paths for groups in conformance tests (#443)

Author: timostamm

tools/protovalidate-conformance/internal/fieldpath/fieldpath.go

@@ -83,17 +83,24 @@ func Unmarshal(
 			}
 			descriptor = extension.TypeDescriptor()
 		} else {
-			descriptor = message.Fields().ByTextName(name)
+			descriptor = message.Fields().ByName(protoreflect.Name(name))
 			oneOf = message.Oneofs().ByName(protoreflect.Name(name))
 		}
 		var element *validate.FieldPathElement
 		switch {
-		case descriptor != nil:
+		case isExt:
+
 			element = &validate.FieldPathElement{
 				FieldNumber: proto.Int32(int32(descriptor.Number())),
 				FieldName:   proto.String(descriptor.TextName()),
 				FieldType:   descriptorpb.FieldDescriptorProto_Type(descriptor.Kind()).Enum(),
 			}
+		case descriptor != nil:
+			element = &validate.FieldPathElement{
+				FieldNumber: proto.Int32(int32(descriptor.Number())),
+				FieldName:   proto.String(string(descriptor.Name())),
+				FieldType:   descriptorpb.FieldDescriptorProto_Type(descriptor.Kind()).Enum(),
+			}
 		case oneOf != nil:
 			element = &validate.FieldPathElement{
 				FieldName: proto.String(string(oneOf.Name())),