feat: add oraReminder message to notification preferences

[awais-ansari]

This PR adds a new message key, oraReminder, to the notification preferences messages. This key will be used to display essay assignment reminders in the notification types.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 68.73%. Comparing base (23d1fce) to head (9fb7657).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1435   +/-   ##
=======================================
  Coverage   68.73%   68.73%           
=======================================
  Files         119      119           
  Lines        2357     2357           
  Branches      646      643    -3     
=======================================
  Hits         1620     1620           
  Misses        692      692           
  Partials       45       45           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.