FE - Fix bitbucket new project form

What does this MR do and why?

In relation to the new panel-based UI.

This fixes the input elements that were previously overlapping when the screen is at tablet size. When you have duo chat open to the right and the import page content is smaller, the labels should be clearly seen.

References

Overall epic -> https://gitlab.com/groups/gitlab-org/-/epics/18787

Import-specific epic- > https://gitlab.com/groups/gitlab-org/-/epics/19396

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Have the panel-based UI feature flags on for your user -> tailwind_container_queries and paneled_view
2. and Duo chat enabled (you'd need an enterprise instance)
3. Navigate to /import/bitbucket_server/new
4. open duo chat panel and change screen size (or use the mobile responsiveness feature in dev tools)

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #572698 (closed)