Feature/fix export on url (#4823)

* added callbacks

* added back callback to main

* added save_dir to callback output

* merged in upstream

* removed ghost code

* added url check

* Add url2file()

* Update file-only

Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

utils/general.py

@@ -360,6 +360,13 @@ def check_dataset(data, autodownload=True):
     return data  # dictionary
 
 
+def url2file(url):
+    # Convert URL to filename, i.e. https://url.com/file.txt?auth -> file.txt
+    url = str(Path(url)).replace(':/', '://')  # Pathlib turns :// -> :/
+    file = Path(urllib.parse.unquote(url)).name.split('?')[0]  # '%2F' to '/', split https://url.com/file.txt?auth
+    return file
+
+
 def download(url, dir='.', unzip=True, delete=True, curl=False, threads=1):
     # Multi-threaded file download and unzip function, used in data.yaml for autodownload
     def download_one(url, dir):