A11y_AzureNotebooks_Jupyter_NBExtensionsTab_ScreenReader: Narrator focus is not shifting inside the "Filter Edit Combobox" items.

[AccessibilityTestingTeam-TCS]

EnvironmentDetails:
Application Name:AzureNotebooks_Jyupter
Login Url: notebooks.azure.com
BrowserDetails:
Edge:Microsoft Edge 41.16299.611.0
Chrome:Version 68.0.3440.106
Operating System:Windows10

Steps to reproduce:
1.Login with the appropriate credentials to azure notebook account.
2.Go to Get started à libraries à Select any of the libraries à click on clone to clone the library
3.Click on Run or right click and select Run to run the notebook.
4.Navigate to NBExtensionTab
5.Start the narrator
6.Use keyboard to navigate to Filter Edit Combobox.

Actual:
Issue 1
Narrator focus is not shifting inside the "Filter Edit Combobox" items.
Issue 2
NVDA is not reading "Filter Edit Combobox" items.

Expected:
Issue 1
Narrator focus should shift inside the "Filter Edit Combobox" and reads items.
Issue 2
NVDA should read "Filter Edit Combobox" items.

UserImpact:
User will not be able to access the Filter Edit Combobox

Attachment:
(https://github.com/jupyter/notebook/files/2400136/A11y_AzureNotebooks_Jupyter_NBExtensionsTab_ScreenReader1.pptx)
(https://github.com/jupyter/notebook/files/2400151/A11y_AzureNotebooks_Jupyter_NBExtensionsTab_ScreenReader2.pptx)

[jtpio]

Closing as there are now different issues tracking accessibility improvements for Jupyter Notebook 7, for example #6800

Thanks!