Close feature overview before popup

[AdvancedImagingUTSW]

Describe the bug
If you are configuring a custom acquisition, and you close the custom acquisition interface before closing a pop-up for a specific feature, it throws a tk error.

For example, open this:

Then after selecting this:

Close the original window, and then try to close the second popup window that is derived from it.

Exception in Tkinter callback
Traceback (most recent call last):
  File "/opt/miniconda3/envs/navigate/lib/python3.9/tkinter/__init__.py", line 1892, in __call__
    return self.func(*args)
  File "/Users/S155475/Desktop/GitHub/navigate/src/navigate/controller/sub_controllers/features_popup_controller.py", line 437, in <lambda>
    "WM_DELETE_WINDOW", lambda: update_feature_parameters(popup)
  File "/Users/S155475/Desktop/GitHub/navigate/src/navigate/controller/sub_controllers/features_popup_controller.py", line 519, in update_feature_parameters
    self.update_feature_content()
  File "/Users/S155475/Desktop/GitHub/navigate/src/navigate/controller/sub_controllers/features_popup_controller.py", line 251, in update_feature_content
    self.feature_content_view.delete("1.0", tk.END)
  File "/opt/miniconda3/envs/navigate/lib/python3.9/tkinter/__init__.py", line 3602, in delete
    self.tk.call(self._w, 'delete', index1, index2)
_tkinter.TclError: invalid command name ".!popup.!frame.!text"