Important: #90264 - Initialize datepicker JS in external file

See forge#90264


The initialization of the datepicker has been moved into an external file residing in EXT:form/Resources/Public/JavaScript/Frontend/DatePicker.js. Some installations might restrict requesting public resources from /typo3/. Therefore, a new YAML configuration has been introduced:

That way, integrators are able to move the file to a different folder which is publicly accessible.