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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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,
if (!wallet) return NullUniValue;
    CWallet* const pwallet = wallet.get();
    if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Cannot import private keys to a wallet with private keys disabled");
    }
    EnsureLegacyScriptPubKeyMan(*wallet, true);
    WalletRescanReserver reserver(*pwallet);
    bool fRescan = true;
    {
        LOCK(pwallet->cs_wallet);
        EnsureWalletIsUnlocked(pwallet);
        std::string strSecret = request.params[0].get_str();
        std::string strLabel = "";
        if (!request.params[1].isNull())
            strLabel = request.params[1].get_str();
        
        if (!request.params[2].isNull())
            fRescan = request.params[2].get_bool();
        if (fRescan && pwallet->chain().havePruned()) {
            
            
            
            throw JSONRPCError(RPC_WALLET_ERROR, "Rescan is disabled when blocks are pruned");
        }
        if (fRescan && !reserver.reserve()) {
            throw JSONRPCError(RPC_WALLET_ERROR, "Wallet is currently rescanning. Abort existing rescan or wait.");
        }
        CKey key = DecodeSecret(strSecret);
        if (!key.IsValid()) throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid private key encoding");
        CPubKey pubkey = key.GetPubKey();