Siderbar: Add shortcut button inaccessible by keyboard only users.

Issue Summary

The element  "Add shortcut" button is not accessible by keyboard alone in the sidebar of the Repository.

Steps to Reproduce

1. Launch the URL
2. Navigate to the sidebar of the repository.
3. Navigate to the "Add shortcut" button and try to activate it with the keyboard.

Screenshot

Actual Results

In the sidebar of the Repository, the Keyboard support is missing for the "Add shortcut" button. When the user tries to access the button with the keyboard it does not perform any functionality, whereas when activated with the mouse it opens a modal. This made it difficult for keyboard-only and screen reader users to access the functionality associated with the button. 

Expected Results

Modify the scripts associated with the buttons to ensure that it is accessible for keyboard-only and screen reader users. Additionally, provide the textual description for the button as "Add shortcut" via the aria-label attribute. 

Workaround

Currently, there is no known workaround for this behaviour. A workaround will be added here when available

Bug Ref: 741399