Add CQ utils to MQ utils rather than replace them

What does this MR do and why?

Add CQ utils to MQ utils rather than replace them

This updates the container queries migration script to add container queries utils to existing media queries utils rather than replace them. This should make it safer to migrate shared components as we won't need to worry about pages that might use them but don't have CQs enabled yet.

Note

Currently, container queries are generated before media queries within the Tailwind CSS bundle. This means that the latter will always take precedence whether there is a container or not. We actually want container queries to be prioritized, which would require moving them after media queries in the bundle. The only way I found to do this is to write a PostCSS plugin in gitlab-org/gitlab-services/design.gitlab.com!4963 (closed). Once that other MR is merged, we'd need to consume the plugin here in GitLab.

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