Auto-scroll to top of page upon committing in pipeline editor

What does this MR do?

For #300028 (closed).

When a user commits on the pipeline editor, the page will automatically scroll up after the commit to bring the user's attention to the alert component (which will show either the error message or a success confirmation). This is especially useful UX for users working on a long commit file, who may not notice the success alert because it's not on screen.

Screenshots

On successful commit Auto-scroll on success

On failed commit (sample error for demonstration) Auto-scroll on error

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

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