Add list_display customization to the reports view

This allows us to access the reported post's body, subject, etc for
in-line display. It ain't perfect, but it definitely is better than
nothing.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

board/admin.py

@@ -1,4 +1,5 @@
 from django.contrib import admin
+from django.utils.safestring import mark_safe
 from board.models import Board, Post, ReportReason, Report
 
 
@@ -20,4 +21,17 @@ class ReportReasonAdmin(admin.ModelAdmin):
 @admin.register(Report)
 class ReportAdmin(admin.ModelAdmin):
     readonly_fields = ("post", "reason", "ip")
+    list_display = ("_post_thumbnail", "_post_subject", "_post_body")
     save_as = False
+
+    def _post_thumbnail(self, obj):
+        if obj.post.thumbnail:
+            return mark_safe(f'<img src="{obj.post.thumbnail.url}" />')
+        else:
+            return None
+
+    def _post_subject(self, obj):
+        return obj.post.subject
+
+    def _post_body(self, obj):
+        return obj.post.text