Improve vulnerability filter component logic

What does this MR do?

On the security dashboard, there are filters that will filter the list of vulnerabilities:

These filters have a parent first_class_vulnerability_filters.vue component that has a list of filters:

Previously, this parent component did all the heavy lifting, and each filter only emitted an event when an option in it was clicked:

This meant that each filter needed to follow the same format and behavior:

However, now we need to add new filters that have different behavior:

Scanner filter	Activity filter

To make it easier to create filters with different behavior from the standard filter, this MR moves most of the logic from teh parent component into the filter itself:

This lets us create new filters with custom behavior, because each filter's behavior is now self-contained rather than relying on a parent component to handle it. An example of a custom filter can be seen in this MR: !46540 (merged)

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

Relates to #229661 (closed)