Add custom scanner filter to security dashboard

What does this MR do?

On the security dashboard, we have a scanner filter:

Previously, this filter showed a list of hard-coded values. Now, we have projects that can have custom security scanners. We need to add these custom scanners to the list so that users can filter by them. The list of custom scanners is retrieved through GraphQL, and is combined with the list of hard-coded values. The list also needs to be grouped by vendor.

Before	After

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

related issue #229661 (closed)