Add new input to file field

Hello

that was in my mind when micker proposed to make multi-property field with multiple values, that also makes use of fileselement view (for selecting FLEXIcontent files)

there will be a field file_extended in future release that will be backward compatibile with values of "file" thus you should be able to change an existing field from file to "file_extended"

Hi,

In my case, I adapted the field to my needs, and work (for now lol) but I have same issues I try solved in future.