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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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,
UniValue warnings(UniValue::VARR);
    UniValue result(UniValue::VOBJ);
    try {
        if (!data.exists("desc")) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Descriptor not found.");
        }
        const std::string& descriptor = data["desc"].get_str();
        const bool active = data.exists("active") ? data["active"].get_bool() : false;
        const bool internal = data.exists("internal") ? data["internal"].get_bool() : false;
        const std::string& label = data.exists("label") ? data["label"].get_str() : "";
        
        FlatSigningProvider keys;
        std::string error;
        auto parsed_desc = Parse(descriptor, keys, error,  true);
        if (!parsed_desc) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
        }
        
        int64_t range_start = 0, range_end = 1, next_index = 0;
        if (!parsed_desc->IsRange() && data.exists("range")) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Range should not be specified for an un-ranged descriptor");
        } else if (parsed_desc->IsRange()) {
            if (data.exists("range")) {
                auto range = ParseDescriptorRange(data["range"]);
                range_start = range.first;
                range_end = range.second + 1; 
            } else {
                warnings.push_back("Range not given, using default keypool range");
                range_start = 0;
                range_end = gArgs.GetArg("-keypool", DEFAULT_KEYPOOL_SIZE);