Generate a FileCollection from a FileList
FileList is the native API from the browser however in order to use this function
the File need the webkitRelativePath property. This property is added by the browser
if the input element has the webkitdirectory property like for example
`'
By default this method will expand all zip and gzip files
Parameters
fileList: FileList
iterable object obtained using a input type="file" with webkitRelativePath property
Generate a FileCollection from a FileList FileList is the native API from the browser however in order to use this function the File need the webkitRelativePath property. This property is added by the browser if the input element has the webkitdirectory property like for example `' By default this method will expand all zip and gzip files