UI for deleting many files

[dalito]

While preparing large datasets, it is sometimes required to remove all datafiles and re-upload. For example, we uploaded xlsx first but found out that dataverse does not display them well. So we decided to switch to csv. We had to delete ~200 files.

The UI only supports deleting a maximum of 50 at a time due to pagination. There should be an option to select all files in the dataset, not just all on the page of the paginated view.