feat: Settings screen for custom branding (#8543)

- Ability to configure Chatwoot custom branding from UI when using paid plans

Co-authored-by: Nithin David Thomas <1277421+nithindavid@users.noreply.github.com>

enterprise/app/controllers/enterprise/super_admin/app_configs_controller.rb

@@ -0,0 +1,23 @@
+module Enterprise::SuperAdmin::AppConfigsController
+  private
+
+  def allowed_configs
+    return super if ChatwootHub.pricing_plan == 'community'
+
+    case @config
+    when 'custom_branding'
+      @allowed_configs = %w[
+        LOGO_THUMBNAIL
+        LOGO
+        BRAND_NAME
+        INSTALLATION_NAME
+        BRAND_URL
+        WIDGET_BRAND_URL
+        TERMS_URL
+        PRIVACY_URL
+      ]
+    else
+      super
+    end
+  end
+end