fix: create ghost msg/emoji entities if not found

The problem here is with the lookup-refs. Some times reaction data
refers to message-keys which are not existing, this can happen for older
messages which aren't in our archives.

So by passing the lookup ref as maps datomic will create an entitify
if it doesn't exist.

Author: oxalorg

src/clojurians_log/db/import.clj

@@ -95,13 +95,11 @@
            :url       url})
 
 (defmethod event->tx ["reaction_added" nil] [{:keys [user item reaction item_user event_ts ts]}]
-  ;; Placeholder just to show that we're getting some data.
-  ;; TODO: return Datomic transaction data to create a reaction entity
   {:reaction/type "reaction_added"
-   :reaction/emoji [:emoji/shortcode reaction]
+   :reaction/emoji {:emoji/shortcode reaction}
    :reaction/ts ts
    :reaction/user [:user/slack-id user]
-   :reaction/message [:message/key (message-key item)]})
+   :reaction/message {:message/key (message-key item)}})
 
 (defmethod event->tx ["reaction_removed" nil] [{:keys [user item reaction item_user event_ts ts]}]
   ;; Placeholder just to show that we're getting some data.