Change show more button to be a table row

What does this MR do?

Make "Show more" button a table row instead.

Previously, in MR !38733 (merged), the show more button was created below the table and we had to a bunch of style classes to make it look like a table row. In this MR, we remove the style class and created the show more button as a table row instead.

This will also resolve the radius issue because the show more button is an actual table row > #234183 (closed)

Screenshots

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

Closes #235672 (closed) #234183 (closed)