feat: Add liquid processing for SMS campaigns (#10981)

Liquid template processing for SMS campaigns
fixes: https://github.com/chatwoot/chatwoot/issues/10980

Co-authored-by: Sojan Jose <sojan@pepalo.com>

app/services/liquid/campaign_template_service.rb

@@ -0,0 +1,26 @@
+class Liquid::CampaignTemplateService
+  pattr_initialize [:campaign!, :contact!]
+
+  def call(message)
+    process_liquid_in_content(message_drops, message)
+  end
+
+  private
+
+  def message_drops
+    {
+      'contact' => ContactDrop.new(contact),
+      'agent' => UserDrop.new(campaign.sender),
+      'inbox' => InboxDrop.new(campaign.inbox),
+      'account' => AccountDrop.new(campaign.account)
+    }
+  end
+
+  def process_liquid_in_content(drops, message)
+    message = message.gsub(/`(.*?)`/m, '{% raw %}`\\1`{% endraw %}')
+    template = Liquid::Template.parse(message)
+    template.render(drops)
+  rescue Liquid::Error
+    message
+  end
+end