Resolve "GitLab Migration - migrations with status timeout (3) are not updated in the UI"

What does this MR do and why?

This MR adds handling of timeout status for Gitlab Migration Related to #358153 (closed)

Screenshots or screen recordings

How to set up and validate locally

• Open "New group" -> Import (/groups/new)
• Use https://gitlab.com as source instance and GeK1Nis4j-SY1X4sqE5c as personal access token (this token is from separate user on GitLab instance with 0 real data available, so we do not expose any security risks here)
• Initiate new import and wait it to become "complete"
• Open bundle exec rails console
• Run

m = BulkImport.last
m.status = 3
m.save

(3 is timeout)

• Refresh page, observe timeout status

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.