While working on this PR https://github.com/bitcoin/bitcoin/pull/18570 I ran into a bit confusing situation where in one function a **CWallet reference** was expected while two others dealt with **CWallet pointers**. My initial reaction was: `let's harmonize them by making them references`. However, not being part of the PR itself I did't change anything and completed the PR first.

Now, after having analyzed the `rpcwallet.cpp` code I came to the conclusion that:

* converting them all into references is not the solution as they're originally **shared_ptr**s
* but also: there is no (visible) reason why every RPC function should begin like this:

```cpp
std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(request);
const CWallet* const pwallet = wallet.get();
```

This clearly defeats the purpose of shared pointers for no obvious reason. *Maybe I am missing something?*

In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept their original names (that is, *pwallet*). In the end, they're pointers too, so the most of the original code remained untouched.

However, some of the helper functions couldn't be changed because external code is accessing them and I didn't want to make this task "virulent". So I introduced new ("Ref") variants that expect **shared_ptr** parameters, namely: 

```cpp
void EnsureWalletRefIsUnlocked(const std::shared_ptr<CWallet>);
bool EnsureWalletRefIsAvailable(const std::shared_ptr<CWallet>, bool avoidException);
```

I have tested the code, with python and boost-tests, and could not find any errors. 
But before opening a PR I would like to open a discussion about this. 

Is there any reason to keep on working with raw pointers when every function call actually begins with *shared_ptr*s?

Regards,
{
    bool want_psbt = method_name == "psbtbumpfee";
    const std::string incremental_fee{CFeeRate(DEFAULT_INCREMENTAL_RELAY_FEE).ToString(FeeEstimateMode::SAT_VB)};
    return RPCHelpMan{method_name,
        "\nBumps the fee of an opt-in-RBF transaction T, replacing it with a new transaction B.\n"
        + std::string(want_psbt ? "Returns a PSBT instead of creating and signing a new transaction.\n" : "") +
        "An opt-in RBF transaction with the given txid must be in the wallet.\n"
        "The command will pay the additional fee by reducing change outputs or adding inputs when necessary.\n"
        "It may add a new change output if one does not already exist.\n"
        "All inputs in the original transaction will be included in the replacement transaction.\n"
        "The command will fail if the wallet or mempool contains a transaction that spends one of T's outputs.\n"
        "By default, the new fee will be calculated automatically using the estimatesmartfee RPC.\n"
        "The user can specify a confirmation target for estimatesmartfee.\n"
        "Alternatively, the user can specify a fee rate in " + CURRENCY_ATOM + "/vB for the new transaction.\n"
        "At a minimum, the new fee rate must be high enough to pay an additional new relay fee (incrementalfee\n"
        "returned by getnetworkinfo) to enter the node's mempool.\n"
        "* WARNING: before version 0.21, fee_rate was in " + CURRENCY_UNIT + "/kvB. As of 0.21, fee_rate is in " + CURRENCY_ATOM + "/vB. *\n",
        {
            {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The txid to be bumped"},
            {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                {
                    {"conf_target", RPCArg::Type::NUM,  "wallet -txconfirmtarget", "Confirmation target in blocks\n"},