Hide scan details when no report summary scans are available

What does this MR do and why?

At times when the report summary is empty, but the pipeline has started, the scan details component would still show. However, when clicking "Show details", expanding would not show any results – as there are none.

This MR improves adds a computed property to see if there are any scans in the report summary and uses that to hide the scan details (and other scan components) if necessary.

Screenshots or screen recordings

before	after
before-scan-details

How to set up and validate locally

You'll need an EE license and runners set up. Make sure runners are up

1. import security-reports
2. create MR with some fake change
3. in another tab, go to /admin/runners and pause the runner
4. in the created MR, click on the pipeline number
5. click "security" tab and validate the "Scan details" component is not shown
6. un-pause the runner at /admin/runners
7. wait until pipeline from MR is finished and load "security" tab again
8. validate that scan details is shown now and you can click "show details" to expand

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Closes #384346 (closed)