feat(librarium): Announcement management page

[MathewEm]

This pull request adds AnnouncementResources, and associated Announcement page modification files to the Librarium. These additions allow for announcements to be created, edited, and deleted as per #893 .

Frontend Changes

• Announcement tab now present in Librarium dashboard
• Announcement index page displays tables containing Past, Current, and Upcoming announcements with creation, edit, and deletion buttons
• Announcement index page allows for viewing or editing of full details of an announcements in a popup window
• Announcement creation page contains form with required attributes for the creation of an announcement

Backend Changes

• AnnouncementResources.php implements creation form with validation and viewable table
• The Announcement model now has title, text, and duration date attributes added to the $fillable array for mass assignment by Librarium
• CreateAnnouncement.php adds a T23:59:59 time-element to end_at to force all announcements to end at end-of-day UTC
• The EditAction method adds a T23:59:59 time-element to end_at if configured to force announcement to end at end-of-day UTC

[enlightn-for-laravel]

⚠️ 1 Checks Failed!

🛡️ 1 Security Vulnerabilities
🚀 0 Performance Issues
🐛 0 Reliability Issues

You may view the full report here.

[enlightn-for-laravel]

✔️ All Checks Passed!

🛡️ 0 Security Vulnerabilities
🚀 0 Performance Issues
🐛 0 Reliability Issues

You may view the full report here.

[vincentauger]

Looks great!