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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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,
WalletContext& context = EnsureWalletContext(request.context);
    uint64_t flags = 0;
    if (!request.params[1].isNull() && request.params[1].get_bool()) {
        flags |= WALLET_FLAG_DISABLE_PRIVATE_KEYS;
    }
    if (!request.params[2].isNull() && request.params[2].get_bool()) {
        flags |= WALLET_FLAG_BLANK_WALLET;
    }
    SecureString passphrase;
    passphrase.reserve(100);
    std::vector<bilingual_str> warnings;
    if (!request.params[3].isNull()) {
        passphrase = request.params[3].get_str().c_str();
        if (passphrase.empty()) {
            
            warnings.emplace_back(Untranslated("Empty string given as passphrase, wallet will not be encrypted."));
        }
    }
    if (!request.params[4].isNull() && request.params[4].get_bool()) {
        flags |= WALLET_FLAG_AVOID_REUSE;
    }
    if (!request.params[5].isNull() && request.params[5].get_bool()) {
#ifndef USE_SQLITE
        throw JSONRPCError(RPC_WALLET_ERROR, "Compiled without sqlite support (required for descriptor wallets)");
#endif
        flags |= WALLET_FLAG_DESCRIPTORS;
        warnings.emplace_back(Untranslated("Wallet is an experimental descriptor wallet"));
    }
    if (!request.params[7].isNull() && request.params[7].get_bool()) {
#ifdef ENABLE_EXTERNAL_SIGNER