Fix swipe diff divider

What does this MR do?

Moves the swipe frame border to the right on merge request image diff swipe views so that the divider shows up.

In the Vue image diff app, the border needs to be on the right because the new image comes in from the left. The old image diff app which is used in commits and compare views had the new image visible by default and hiding away from the left.

60005-fixed

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance and testing

• Tests added for this feature/bug
• Tested in all supported browsers
• End to end tests added if this MR has ~"Requires e2e tests" label

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

Closes #60005 (closed)