feat: Change slack bot and activity message appearance (#8349)

lib/integrations/slack/send_on_slack_service.rb

@@ -44,7 +44,7 @@ class Integrations::Slack::SendOnSlackService < Base::SendOnChannelService
 
   def message_content
     private_indicator = message.private? ? 'private: ' : ''
-    sanitized_content = ActionView::Base.full_sanitizer.sanitize(message_text)
+    sanitized_content = ActionView::Base.full_sanitizer.sanitize(format_message_content)
 
     if conversation.identifier.present?
       "#{private_indicator}#{sanitized_content}"
@@ -53,6 +53,10 @@ class Integrations::Slack::SendOnSlackService < Base::SendOnChannelService
     end
   end
 
+  def format_message_content
+    message.message_type == 'activity' ? "_#{message_text}_" : message_text
+  end
+
   def message_text
     if message.content.present?
       message.content.gsub(MENTION_REGEX, '\1')
@@ -79,7 +83,7 @@ class Integrations::Slack::SendOnSlackService < Base::SendOnChannelService
   end
 
   def avatar_url(sender)
-    sender_type = sender.instance_of?(Contact) ? 'contact' : 'user'
+    sender_type = sender_type(sender).downcase
     blob_key = sender&.avatar&.attached? ? sender.avatar.blob.key : nil
     generate_url(sender_type, blob_key)
   end
@@ -137,7 +141,15 @@ class Integrations::Slack::SendOnSlackService < Base::SendOnChannelService
   end
 
   def sender_type(sender)
-    sender.instance_of?(Contact) ? 'Contact' : 'Agent'
+    if sender.instance_of?(Contact)
+      'Contact'
+    elsif message.message_type == 'template' && sender.nil?
+      'Bot'
+    elsif message.message_type == 'activity' && sender.nil?
+      'System'
+    else
+      'Agent'
+    end
   end
 
   def update_reference_id