ext/sodium: Add support for libsodium 1.0.21 APIs

Add support for new functions present in recent libsodium
versions:

- Functions for IP address encryption:
  - sodium_crypto_ipcrypt_*
  - sodium_bin2ip/sodium_ip2bin helpers

- Extendable output functions:
  - SHAKE128/SHAKE256
  - TurboSHAKE128/TurboSHAKE256

Author: jedisct1

NEWS

@@ -104,6 +104,9 @@ PHP                                                                        NEWS
   . Fixed GH-20532 (socket_addrinfo_lookup gives the error code with a new
     optional parameter). (David Carlier)
 
+- Sodium:
+  . Added support for libsodium 1.0.21 IPcrypt and XOF APIs. (jedisct1)
+
 - SPL:
   . DirectoryIterator key can now work better with filesystem supporting larger
     directory indexing. (David Carlier)