Upgrade GitLab UI and migrate pagination

What does this MR do?

This upgrades GitLab UI to the latest version. Additionally:

• GlPagination usage has been migrated. GlPagination now uses chevron icons for the previous and next page items, thus we don't need the ‹ and › special characters in those pagination items' labels. gitlab-ui!1098 (merged)
• Some snapshots had to be updated to account for changes in GlLoadingIcon. gitlab-ui!1102 (diffs)
• Some snapshots and a test had to be updated to account for change in GlButton: gitlab-ui!1102 (diffs)

Screenshots

Before	After

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