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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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,
CWallet* const pwallet = wallet.get();
    LOCK(pwallet->cs_wallet);
    uint256 hash(ParseHashV(request.params[0], "txid"));
    std::vector<uint256> vHash;
    vHash.push_back(hash);
    std::vector<uint256> vHashOut;
    if (pwallet->ZapSelectTx(vHash, vHashOut) != DBErrors::LOAD_OK) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Could not properly delete the transaction.");
    }
    if(vHashOut.empty()) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Transaction does not exist in wallet.");
    }
    return NullUniValue;
},
    };
}
RPCHelpMan importpubkey()
{
    return RPCHelpMan{"importpubkey",
                "\nAdds a public key (in hex) that can be watched as if it were in your wallet but cannot be used to spend. Requires a new wallet backup.\n"
                "Hint: use importmulti to import more than one public key.\n"
            "\nNote: This call can take over an hour to complete if rescan is true, during that time, other rpc calls\n"
            "may report that the imported pubkey exists but related transactions are still missing, leading to temporarily incorrect/bogus balances and unspent outputs until rescan completes.\n"
            "Note: Use \"getwalletinfo\" to query the scanning progress.\n",
                {
                    {"pubkey", RPCArg::Type::STR, RPCArg::Optional::NO, "The hex-encoded public key"},
                    {"label", RPCArg::Type::STR,  "\"\"", "An optional label"},
                    {"rescan", RPCArg::Type::BOOL,  "true", "Rescan the wallet for transactions"},
                },
                RPCResult{RPCResult::Type::NONE, "", ""},