Add missing email errors (#5264)

stdlib/email/errors.pyi

@@ -1,3 +1,4 @@
+import sys
 from typing import Optional
 
 class MessageError(Exception): ...
@@ -5,6 +6,7 @@ class MessageParseError(MessageError): ...
 class HeaderParseError(MessageParseError): ...
 class BoundaryError(MessageParseError): ...
 class MultipartConversionError(MessageError, TypeError): ...
+class CharsetError(MessageError): ...
 
 class MessageDefect(ValueError):
     def __init__(self, line: Optional[str] = ...) -> None: ...
@@ -14,9 +16,25 @@ class StartBoundaryNotFoundDefect(MessageDefect): ...
 class FirstHeaderLineIsContinuationDefect(MessageDefect): ...
 class MisplacedEnvelopeHeaderDefect(MessageDefect): ...
 class MultipartInvariantViolationDefect(MessageDefect): ...
+class InvalidMultipartContentTransferEncodingDefect(MessageDefect): ...
+class UndecodableBytesDefect(MessageDefect): ...
 class InvalidBase64PaddingDefect(MessageDefect): ...
 class InvalidBase64CharactersDefect(MessageDefect): ...
+class InvalidBase64LengthDefect(MessageDefect): ...
 class CloseBoundaryNotFoundDefect(MessageDefect): ...
 class MissingHeaderBodySeparatorDefect(MessageDefect): ...
 
 MalformedHeaderDefect = MissingHeaderBodySeparatorDefect
+
+class HeaderDefect(MessageDefect): ...
+class InvalidHeaderDefect(HeaderDefect): ...
+class HeaderMissingRequiredValue(HeaderDefect): ...
+
+class NonPrintableDefect(HeaderDefect):
+    def __init__(self, non_printables: Optional[str]) -> None: ...
+
+class ObsoleteHeaderDefect(HeaderDefect): ...
+class NonASCIILocalPartDefect(HeaderDefect): ...
+
+if sys.version_info >= (3, 10):
+    class InvalidDateDefect(HeaderDefect): ...