[AB-xxx] adding avatar to message embed

adding avatar to starboard post
adding possibility to define a color for the starboard container
fixing attachment logic for starboard post
fixing streamer went offline message not using components v2

abstracto-modules/twitch/src/main/resources/default/general/twitch_streamer_went_offline_message_embed.ftl

@@ -1,18 +1,37 @@
 <#include "format_instant">
 {
-    "embeds": [
+    "components": [
         {
-            <#include "twitch_color">,
             <#assign channelName=channelName>
             <#assign avatarURL=avatarURL>
-            "title": {
-                "title": "<@safe_include "twitch_streamer_went_offline_notification_title"/>"
-            },
-            "author": { "name": "${channelName}", "avatar":  "${avatarURL}"},
-            "description": "<@safe_include "twitch_streamer_went_offline_notification_past_sections"/>"
-            <#if offlineImageURL??>,
-            <#assign offlineImageURL=offlineImageURL>
-            "imageUrl": "${offlineImageURL}"</#if>
+            "type": "section",
+            "components": [
+                {
+                    "type": "textDisplay",
+                    "content": "<@safe_include "twitch_streamer_went_offline_notification_title"/>"
+                },
+                {
+                    "type": "textDisplay",
+                    "content": "<@safe_include "twitch_streamer_went_offline_notification_past_sections"/>"
+                }
+            ]
+            ,"accessory": {
+                "type": "thumbnail",
+                "url": "${avatarURL}"
+            }
         }
-    ]
+        <#if offlineImageURL??>,
+        {
+            "type": "mediaGallery",
+            "images": [
+                {
+                    "url": "${offlineImageURL}"
+                }
+            ]
+        }
+        </#if>
+    ],
+    "messageConfig": {
+        "useComponentsV2": true
+    }
 }