Improve UX of project import page
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### Problem to solve
https://gitlab.com/gitlab-org/gitlab/-/issues/352707 addresses some UX issues with the `disabled` state for the gitlab and bitbucket import buttons, as a follow-up it was also noted that if possible we should look to. standardize the import interaction UI when clicking the various buttons
Following on from the conversation in https://gitlab.com/gitlab-org/gitlab/-/issues/352707#note_850900960+
### Proposal
We should do some investigation into how we can improve the ~UX of the page, currently it's unclear the type of action that might occur when a button is clicked, actions can include:
- Inline form appearing
- Redirect to a different form
- Redirect to a new page
- Modal message popup
issue