Resolve "Remove non-semantic use of `.row` in member listing controls"

What does this MR do?

Removes non-semantic use of .row that removes side padding from member controls container in the shared member list introduced in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/12304.

Screenshots

Before

After

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Separation of EE specific content

Performance and testing

• Tested in all supported browsers

Closes #11542 (closed)