feat: Slack link unfurling (#7940)

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

lib/integrations/slack/slack_message_helper.rb

@@ -62,4 +62,17 @@ module Integrations::Slack::SlackMessageHelper
       :file
     end
   end
+
+  def conversation
+    @conversation ||= Conversation.where(identifier: params[:event][:thread_ts]).first
+  end
+
+  def sender
+    user_email = slack_client.users_info(user: params[:event][:user])[:user][:profile][:email]
+    conversation.account.users.find_by(email: user_email)
+  end
+
+  def private_note?
+    params[:event][:text].strip.downcase.starts_with?('note:', 'private:')
+  end
 end