Upgrade GitLab UI to v16.2.1 & Bootstrap to v4.4.1

• Related issue: gitlab-ui#733 (closed)
• Integration MR for: gitlab-ui!1354 (merged)

What does this MR do?

Upgrades Bootstrap to v4.4.1 and GitLab UI to next version which comes with BootstrapVue v2.13.1.

Screenshots

Modals

The GlModal component is affected by a change to Bootstrap's modals footer in v4.4.0:

Updated our spacing and alignment for modal footer elements like buttons to automatically wrap when space is constrained.

More information: Enable wrapping for elements in modal-footer

	Before (Bootstrap 4.3.1)	After (Bootstrap 4.4.1)
Status modal
Delete pipeline modal

Group list items

A change to Bootstrap's group list items borders style caused a small visual diff in the GlPaginatedList component because the first item doesn't have a top border anymore.

More information: Fix group list items borders overlapping

	Before (Bootstrap 4.3.1)	After (Bootstrap 4.4.1)
License compliance policies

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