#14062: fix BytesParser handling of Header objects

This is a different fix than the 3.2 fix, but the new tests are the same.

This also affected smtplib.SMTP.send_message, which calls BytesParser.
diff --git a/Misc/NEWS b/Misc/NEWS
index 3652d61..45fb967 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,9 @@
 Library
 -------
 
+- Issue #14062: BytesGenerator now correctly folds Header objects,
+  including using linesep when folding.
+
 - Issue #13839: When invoked on the command-line, the pstats module now
   accepts several filenames of profile stat files and merges them all.
   Patch by Matt Joiner.