Update header and table for security config page

What does this MR do?

This MR implements the changes mentioned in this comment on this issue: #207322 (comment 325438347) In graphical form, the changes are (except for the "Remove SAST/DAST abbreviation", it was removed from the requested changes after the screenshot was created):

Changes

This MR is part 1 of 2 MRs and only implements the header and top table changes (everything above "Add this entire thing").

Screenshots

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