addmultisigaddress creates an address respecting the setting, being unable to generate a specific type of address without also adding it to the wallet seems wrong.

I suppose in the future `addresstype` may be refactored to be wallet-specific, which would leave this non-wallet rpc call without an argument. Perhaps there should just be an optional parameter to set it.
#include <wallet/wallet.h>
#include <checkpoints.h>
#include <chain.h>
#include <wallet/coincontrol.h>
#include <consensus/consensus.h>
#include <consensus/validation.h>
#include <fs.h>
#include <key.h>
#include <key_io.h>
#include <keystore.h>
#include <validation.h>
#include <net.h>
#include <policy/fees.h>
#include <policy/policy.h>
#include <policy/rbf.h>
#include <primitives/block.h>
#include <primitives/transaction.h>
#include <script/script.h>
#include <shutdown.h>
#include <timedata.h>
#include <txmempool.h>
#include <utilmoneystr.h>
#include <wallet/fees.h>
#include <wallet/walletutil.h>