Add separator in vulnerability status description

What does this MR do and why?

This MR adds a middot separator between the status and the timestamp in the status description on the vulnerability details page.

Relates to #406532 (closed).

Screenshots or screen recordings

Before	After

How to set up and validate locally

Prerequisites

1. You'll need an EE license
2. You'll need to have runners enabled (See $2408961 for setting up a runner)
3. Import https://gitlab.com/gitlab-examples/security/security-reports
4. Run a pipeline on master

Validate middot

1. Go to vulnerability report of security-reports
2. Select any vulnerability
3. Validate that after status and before timestamp, there's a separator

If you want to validate with dismissal reason, you'll need to enable the feature flag: echo "Feature.enable(:dismissal_reason)" | rails c

Run tests

yarn jest ee/spec/frontend/vulnerabilities/status_description_spec.js

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.