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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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,
CScriptID id;
                    CRIPEMD160().Write(whash.begin(), whash.size()).Finalize(id.begin());
                    CScript witnessScript;
                    if (provider->GetCScript(id, witnessScript)) {
                        entry.pushKV("witnessScript", HexStr(witnessScript));
                    }
                }
            }
        }
        entry.pushKV("scriptPubKey", HexStr(scriptPubKey));
        entry.pushKV("amount", ValueFromAmount(out.tx->tx->vout[out.i].nValue));
        entry.pushKV("confirmations", out.nDepth);
        entry.pushKV("spendable", out.fSpendable);
        entry.pushKV("solvable", out.fSolvable);
        if (out.fSolvable) {
            std::unique_ptr<SigningProvider> provider = pwallet->GetSolvingProvider(scriptPubKey);
            if (provider) {
                auto descriptor = InferDescriptor(scriptPubKey, *provider);
                entry.pushKV("desc", descriptor->ToString());
            }
        }
        if (avoid_reuse) entry.pushKV("reused", reused);
        entry.pushKV("safe", out.fSafe);
        results.push_back(entry);
    }
    return results;
},
    };
}
void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& fee_out, int& change_position, const UniValue& options, CCoinControl& coinControl, bool override_min_fee)