Add ability to dismiss multiple vulnerabilities at once

What does this MR do?

This MR adds the ability to select multiple vulnerabilities on the dashboards and dismiss them all at once.

📼 Video Demo

https://youtu.be/P-WLfoJnJK8 (slightly out of date, see screenshots for up to date UI)

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation
• 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

Closes #35816 (closed)