Fix: fixes for bulk assign buttons

[TheDancingClown]

📝 A short description of the changes

• Adds anchor to redirect to error message on validation failure
• Hides award year dropdown when javascript disabled.
• Updates save_or_load_search! method to include year params. When using the award year dropdown, the search_id is passed in the params but is not updated with the new year param. A check is therefore done to update the search record if the params[:year] does not match.
• When javascript is disabled, a new search record is created. Therefore the search param is removed from the redirect here as we instead use the year from the search record.
• Increases width of the success banner.
• Adds new copy for bulk assign assessors.

🔗 Link to the relevant story (or stories)

• https://app.asana.com/0/1199154381249427/1208415726190878/f

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

[Lubosky]

👍 looks good, just one minor change