flags/appeals: replace is_resolved flag with statuses.

Replace references to the `is_resolved` field with the `status` field.
Post flags were marked as resolved when a post was approved (but not
when the post was deleted because it went unapproved). The status field
supercedes the resolved field.

app/models/post_event.rb

@@ -30,10 +30,6 @@ class PostEvent
     event.try(:reason) || ""
   end
 
-  def is_resolved
-    event.try(:is_resolved) || false
-  end
-
   def creator_id
     event.try(:creator_id) || event.try(:user_id)
   end
@@ -42,6 +38,18 @@ class PostEvent
     event.try(:creator) || event.try(:user)
   end
 
+  def status
+    if event.is_a?(PostApproval)
+      "approved"
+    elsif (event.is_a?(PostAppeal) && event.succeeded?) || (event.is_a?(PostFlag) && event.rejected?)
+      "approved"
+    elsif (event.is_a?(PostAppeal) && event.rejected?) || (event.is_a?(PostFlag) && event.succeeded?)
+      "deleted"
+    else
+      "pending"
+    end
+  end
+
   def is_creator_visible?(user = CurrentUser.user)
     case event
     when PostAppeal, PostApproval
@@ -57,7 +65,7 @@ class PostEvent
       "creator_id": nil,
       "created_at": nil,
       "reason": nil,
-      "is_resolved": nil,
+      "status": nil,
       "type": nil
     }
   end