fix: add workbook and view setter for custom view

Closes #1729

Add setter methods for workbook and view properties.

Author: jorwoods

tableauserverclient/models/custom_view_item.py

@@ -158,10 +158,18 @@ def owner(self, value: UserItem):
     def workbook(self) -> Optional[WorkbookItem]:
         return self._workbook
 
+    @workbook.setter
+    def workbook(self, value: WorkbookItem) -> None:
+        self._workbook = value
+
     @property
     def view(self) -> Optional[ViewItem]:
         return self._view
 
+    @view.setter
+    def view(self, value: ViewItem) -> None:
+        self._view = value
+
     @classmethod
     def from_response(cls, resp, ns, workbook_id="") -> Optional["CustomViewItem"]:
         item = cls.list_from_response(resp, ns, workbook_id)