Tooltip: Error on inserting sub-objects

[cmeier76]

On initial state (no sub-objects exist) the action-dropdown does not work.

See background infos with example:

• https://github.com/idasm-unibe-ch/unibe-cms/pull/558#issuecomment-1984119268

Introduced by:

• https://github.com/zms-publishing/ZMS/pull/244
• Module Products.zms._zmi_actions_util, line 201, in zmi_insert_actions

  2024-03-07 20:17:47 ERROR [Zope.SiteErrorLog:238][waitress-1] 1709839067.46151110.0830731140386114 https://edit.cmstest3.unibe.ch/unibe/portal/microsites/micro_test/content/e1118829/e1423861/manage_ajaxZMIActions
  Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 181, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 391, in publish_module
  Module ZPublisher.WSGIPublisher, line 285, in publish
  Module ZPublisher.mapply, line 98, in mapply
  Module ZPublisher.WSGIPublisher, line 68, in call_object
  Module Products.zms.zmscontainerobject, line 597, in manage_ajaxZMIActions
  Module Products.zms._zmi_actions_util, line 38, in zmi_actions
  Module Products.zms._zmi_actions_util, line 201, in zmi_insert_actions
  AttributeError: 'NoneType' object has no attribute 'getLangStr'