Certain notifications incorrectly inherit read status from post/topic

When a notification for a post report is created, it's marked as read if the user who's being notified has already read the post that's being reported. This occurs because the report_post class extends post_in_queue which then extends post. The create_insert_array method in the post class sets notification_read as true if the user has already read the post. This also occurs for several other notifications.