User story 27: Superusers can mark collaboration requests as read, so that superusers can see how many still need to be processed

[KSDunne]

As a superuser I can mark collaboration requests as read so that superusers can see how many still need to be processed

Task:

• Implement boolean logic for this in the about > CollaborationRequest model (e.g. read = models.BooleanField(default=False))

Acceptance criteria:

• Acceptance criteria 1: Superusers can view a list of collaboration requests received in the Django admin panel.
• Acceptance criteria 2: Superusers can mark individual collaboration requests as "read" providing a visual indicator to distinguish them from unread requests