scripted-diff: test: Use py3.5 bytes::hex() method

-BEGIN VERIFY SCRIPT-
sed -i -e "s/def bytes_to_hex_str/def b_2_x/g" $(git grep -l bytes_to_hex_str)

export RE_B_0="[^()]*"                          # match no bracket
export RE_B_1="${RE_B_0}\(${RE_B_0}\)${RE_B_0}" # match exactly one ()
export RE_B_2="${RE_B_0}\(${RE_B_1}\)${RE_B_0}" # match wrapped (())

export RE_M="(b2x|bytes_to_hex_str)\(((${RE_B_0}|${RE_B_1}|${RE_B_2})*)\)"

sed -i --regexp-extended -e "s/${RE_M}/\2.hex()/g"      $(git grep -l -E '(b2x|bytes_to_hex_str)')

sed -i --regexp-extended -e "/  +bytes_to_hex_str( as b2x)?,/d"    $(git grep -l bytes_to_hex_str)
sed -i --regexp-extended -e "s/ +bytes_to_hex_str( as b2x)?,//g"   $(git grep -l bytes_to_hex_str)
sed -i --regexp-extended -e "s/, bytes_to_hex_str( as b2x)?//g"    $(git grep -l bytes_to_hex_str)

export RE_M="(binascii\.)?hexlify\(((${RE_B_0}|${RE_B_1}|${RE_B_2})*)\).decode\(${RE_B_0}\)"

sed -i --regexp-extended -e "s/${RE_M}/\2.hex()/g" $(git grep -l hexlify -- ':(exclude)share')

sed -i --regexp-extended -e  "/from binascii import hexlify$/d" $(git grep -l hexlify -- ':(exclude)share')
sed -i --regexp-extended -e "s/(from binascii import) .*hexlify/\1 unhexlify/g" $(git grep -l hexlify -- ':(exclude)share')

sed -i -e 's/ignore-names "/ignore-names "b_2_x,/g' ./test/lint/lint-python-dead-code.sh
-END VERIFY SCRIPT-

test/functional/test_framework/util.py

@@ -5,7 +5,7 @@
 """Helpful routines for regression testing."""
 
 from base64 import b64encode
-from binascii import hexlify, unhexlify
+from binascii import unhexlify
 from decimal import Decimal, ROUND_DOWN
 import hashlib
 import inspect
@@ -182,8 +182,8 @@ def check_json_precision():
 def count_bytes(hex_string):
     return len(bytearray.fromhex(hex_string))
 
-def bytes_to_hex_str(byte_str):
-    return hexlify(byte_str).decode('ascii')
+def b_2_x(byte_str):
+    return byte_str.hex()
 
 def hash256(byte_str):
     sha256 = hashlib.sha256()