[ZEPPELIN-6358] Fix notebook UI bugs and add aria attributes and test IDs for selectors #5101

[dididy]

What is this PR for?

This PR fixes several notebook-related UI issues and improves testability and accessibility.

Changes

• Fix an issue where the search menu trigger did not work correctly.
• Prevent folder renaming when the input is empty by disabling the confirm button.
• Add accessibility (ARIA) attributes and test-specific attributes to improve usability and E2E test stability.

What type of PR is it?

Bug Fix
Refactoring

Todos

What is the Jira issue?

ZEPPELIN-6358

How should this be tested?

Screenshots (if appropriate)

Questions:

• Does the license files need to update? No
• Is there breaking changes for older versions? No
• Does this needs documentation? No