Databus publish wizard bugs for fetching files from url

[JJ-Author]

• duplicate files e.g. when using fetch-urls on github -> needs deduplication e.g. on https://github.com/cenguix/Text2KGBench/tree/48ebb1014b36abcbe457d210919d387cee1d8a6d/data/dbpedia_webnlg/ontologies/owl
• a button to delete all imported files or undo the last fetched imports is missing since you never know what you will get with "fetch url" button
• loading swirls do not disappear once reset form button has been clicked
• reset form button does reset file list (and probably nothing else)