Adds an implementation of XInvocation and XPropertySet to PythonScriptProvider that just passes on all the methods to the wrapped dirBrowseNode. If we don’t do this then the root browser nodes can’t report that they are Editable or Creatable. Change-Id: I2ddab92910ab0cb34866246844669c63b2f66671 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/202851 Tested-by: Jenkins Reviewed-by: Neil Roberts <nroberts@libreoffice.org>