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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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,
CPubKey key(solutions_data[i].begin(), solutions_data[i].end());
                pubkeys.push_back(HexStr(key));
            }
            obj.pushKV("pubkeys", std::move(pubkeys));
        }
    }
    explicit DescribeWalletAddressVisitor(const SigningProvider* _provider) : provider(_provider) {}
    UniValue operator()(const CNoDestination& dest) const { return UniValue(UniValue::VOBJ); }
    UniValue operator()(const PKHash& pkhash) const
    {
        CKeyID keyID{ToKeyID(pkhash)};
        UniValue obj(UniValue::VOBJ);
        CPubKey vchPubKey;
        if (provider && provider->GetPubKey(keyID, vchPubKey)) {
            obj.pushKV("pubkey", HexStr(vchPubKey));
            obj.pushKV("iscompressed", vchPubKey.IsCompressed());
        }
        return obj;
    }
    UniValue operator()(const ScriptHash& scripthash) const
    {
        CScriptID scriptID(scripthash);
        UniValue obj(UniValue::VOBJ);
        CScript subscript;
        if (provider && provider->GetCScript(scriptID, subscript)) {
            ProcessSubScript(subscript, obj);
        }
        return obj;
    }
    UniValue operator()(const WitnessV0KeyHash& id) const