Feature: #86670 - Make default action in DragUploader adjustable

See forge#86670


It is now possible to configure the default action for DragUploader in the file list module using User TSConfig.

# Set default to replace:
options.file_list.uploader.defaultAction = replace

# Set default to rename:
options.file_list.uploader.defaultAction = rename

# Set default to cancel (cancel is also the default and set the option to skip):
options.file_list.uploader.defaultAction = cancel