cli: create GetNewAddress()

Summary:
This is a backport of [[bitcoin/bitcoin#19133 | core#19133]] [3/10]
bitcoin/bitcoin@f7c65a3

Depends on D9942

Test Plan: `ninja`

Reviewers: #bitcoin_abc, majcosta

Reviewed By: #bitcoin_abc, majcosta

Differential Revision: https://reviews.bitcoinabc.org/D9943

src/bitcoin-cli.cpp

@@ -884,6 +884,16 @@ static void GetWalletBalances(UniValue &result) {
     result.pushKV("balances", balances);
 }
 
+/**
+ * Call RPC getnewaddress.
+ * @returns getnewaddress response as a UniValue object.
+ */
+[[maybe_unused]] static UniValue GetNewAddress() {
+    std::unique_ptr<BaseRequestHandler> rh{
+        std::make_unique<DefaultRequestHandler>()};
+    return ConnectAndCallRPC(rh.get(), "getnewaddress", /* args=*/{});
+}
+
 static int CommandLineRPC(int argc, char *argv[]) {
     std::string strPrint;
     int nRet = 0;