partial Merge bitcoin#23002: Make descriptor wallets by default

9c1052a wallet: Default new wallets to descriptor wallets (Andrew Chow)
f19ad40 rpc, wallet: Descriptor wallets are no longer experimental (Andrew Chow)

Pull request description:

  Changes the default wallet type from legacy to descriptors. Descriptor wallets will now by the default type. Additionally, descriptor wallets will no longer be marked as experimental.

  This follows the timeline proposed in bitcoin#20160

ACKs for top commit:
  lsilva01:
    Tested ACK bitcoin@9c1052a on Ubuntu 20.04
  prayank23:
    tACK bitcoin@9c1052a
  meshcollider:
    Code review ACK 9c1052a

Tree-SHA512: 834e6fec88e0c18673af7ebe135bd5333694d1be502164eb93a90e3e76c27974165aa4e59426945100c88e4eca07356e16886ef5b05cf789683ecb23fc71a12a

Author: MarcoFalke

src/wallet/rpc/wallet.cpp

@@ -676,7 +676,6 @@ static RPCHelpMan createwallet()
             throw JSONRPCError(RPC_INVALID_PARAMETER, "The createwallet RPC requires specifying the 'load_on_startup' flag when creating descriptor wallets. Dash Core v21 introduced this requirement due to breaking changes in the createwallet RPC.");
         }
         flags |= WALLET_FLAG_DESCRIPTORS;
-        warnings.emplace_back(Untranslated("Wallet is an experimental descriptor wallet"));
     }
     if (!request.params[7].isNull() && request.params[7].get_bool()) {
 #ifdef ENABLE_EXTERNAL_SIGNER