[Python] Add Support for Content-Disposition Header without filename (#11055)

* [Python] Add Support for CD header w/o filename

* updated documentation per PR instructions

* fixed formatting and updated samples and docs

* revert docs changes

* regenerate python samples

* updated sample python test

samples/openapi3/client/extensions/x-auth-id-alias/python/x_auth_id_alias/model_utils.py

@@ -16,6 +16,7 @@ import os
 import pprint
 import re
 import tempfile
+import uuid
 
 from dateutil.parser import parse
 
@@ -1399,7 +1400,13 @@ def deserialize_file(response_data, configuration, content_disposition=None):
 
     if content_disposition:
         filename = re.search(r'filename=[\'"]?([^\'"\s]+)[\'"]?',
-                             content_disposition).group(1)
+                             content_disposition,
+                             flags=re.I)
+        if filename is not None:
+            filename = filename.group(1)
+        else:
+            filename = "default_" + str(uuid.uuid4())
+
         path = os.path.join(os.path.dirname(path), filename)
 
     with open(path, "wb") as f: