Accessible autocomplete initialization [staging]

[Lubosky]

📝 A short description of the changes

Cherry-picked from #2557
If the field is added dynamically, autocomplete is not initialized properly. Instead the HTML is just copied so it looks like autocomplete but without proper functionality. Initialization then only duplicates the field. So as a solution we just check for any .custom-select select tag, remove already copied autocomplete HTML and re-initialize.

🔗 Link to the relevant story (or stories)

Deployment implications

None

✅ Checklist

• Features that cannot go live are behind a feature flag/env var or specify deploy date and open PR as draft
• I have checked that commit messages make sense and explain the reasoning for each change
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have squashed any unnecessary or part-finished commits

🖼️ Screenshots (if appropriate - no PII/Prod data):