596c446 [wallet] use P2WPKH change output if any destination is P2WPKH or P2WSH (Sjors Provoost)
Pull request description:
If `-changetype` is not explicitly set, then regardless of `-addresstype`, the wallet will use a ~`bech32` change address~ `P2WPKH` change output if any destination is `P2WPKH` or `P2WSH`.
This seems more intuitive to me and more in line with the spirit of [BIP-69](https://github.com/bitcoin/bips/blob/master/bip-0069.mediawiki).
When combined with #11991 a QT user could opt to use `bech32` exclusively without having to figure out how to launch with `-changetype=bech32`, although so would #11937.
Tree-SHA512: 9238d3ccd1f3be8dfdd43444ccf45d6bdc6584ced3172a3045f3ecfec4a7cc8999db0cdb76ae49236492a84e6dbf3a1fdf18544d3eaf6d518e1f8bd241db33e7
Make createmultisig only accept public keys with the old functionality
marked as deprecated.
Splits _createmultisig_redeemscript into two functions, one for
getting public keys from UniValue and one for getting addresses
from UniValue and then their respective public keys. The one for
retrieving address's public keys is located in rpcwallet.cpp
Changes addwitnessaddress's output to be a JSON object with
two fields, address and redeemscript.
Adds a test to deprecated_rpc.py for testing the deprecation.
Update the tests to use addwitnessaddress or give only public keys
to createmultisig. Anything that used addwitnessaddress was also
updated to reflect the new API.
