Implements issue #9951: Adds a hex() method to bytes, bytearray, & memoryview.

Also updates a few internal implementations of the same thing to use the
new built-in code.

Contributed by Arnon Yaari.
diff --git a/Misc/ACKS b/Misc/ACKS
index 0a04a07..ca0fcab 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1547,6 +1547,7 @@
 Robert Xiao
 Florent Xicluna
 Hirokazu Yamamoto
+Arnon Yaari
 Ka-Ping Yee
 Jason Yeo
 EungJun Yi