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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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 (pwallet->IsMine(script) & ISMINE_SPENDABLE) {
                throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already contains the private key for this address or script (\"" + HexStr(script) + "\")");
            }
        }
        
        pwallet->MarkDirty();
        if (!pwallet->ImportScripts(import_data.import_scripts, timestamp)) {
            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding script to wallet");
        }
        if (!pwallet->ImportPrivKeys(privkey_map, timestamp)) {
            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding key to wallet");
        }
        if (!pwallet->ImportPubKeys(ordered_pubkeys, pubkey_map, import_data.key_origins, add_keypool, internal, timestamp)) {
            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
        }
        if (!pwallet->ImportScriptPubKeys(label, script_pub_keys, have_solving_data, !internal, timestamp)) {
            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
        }
        result.pushKV("success", UniValue(true));
    } catch (const UniValue& e) {
        result.pushKV("success", UniValue(false));
        result.pushKV("error", e);
    } catch (...) {
        result.pushKV("success", UniValue(false));
        result.pushKV("error", JSONRPCError(RPC_MISC_ERROR, "Missing required fields"));
    }
    if (warnings.size()) result.pushKV("warnings", warnings);
    return result;
}
static int64_t GetImportTimestamp(const UniValue& data, int64_t now)