FE: After selecting a group, switch back to None yields in an empty page

Steps to reproduce

1. Enable :vulnerability_report_grouping feature flag
2. Go to Vulnerability Report
3. Group by Severity or State
4. Click on a group
5. Switch back to Group by: None

Expected result

We display the default view.

Actual result

An empty page is shown.

Verification steps

• Go to https://gitlab.com/gitlab-org/govern/threat-insights-demos/verification-projects/verify-epic-10164/-/security/vulnerability_report
• Choose a Group (Status for instance)
• Verify the groups are shown
• Switch back to Group None
• Verify the report is displayed