UX polish for pipeline status in pipeline editor

What does this MR do?

A couple of UX polishing from this discussion:

• When there's a commit confirmation alert, there's no space between the status area and the alert. I think we could use 16px distance there.
• The pipeline status icon should be vertically centered related to the text, now it's a bit higher than text

Testing Locally

• Enable the :pipeline_status_for_pipeline_editor feature flag.
• Go to the Pipeline Editor (CI/CD > Editor), make some changes, and commit those changes.
• Verify changes.

Screenshots

Before	After

Before and After Commit

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because the pipeline status feature flag is still disabled.
• [-] 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

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team