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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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 no outputs are specified here, the sender pays the fee.",
                                {
                                    {"vout_index", RPCArg::Type::NUM, RPCArg::Optional::OMITTED, "The zero-based output index, before a change output is added."},
                                },
                            },
                            {"replaceable", RPCArg::Type::BOOL,  "wallet default", "Marks this transaction as BIP125 replaceable.\n"
                                                          "Allows this transaction to be replaced by a transaction with higher fees"},
                            {"conf_target", RPCArg::Type::NUM,  "wallet -txconfirmtarget", "Confirmation target in blocks"},
                            {"estimate_mode", RPCArg::Type::STR,  "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
                            "       \"" + FeeModes("\"\n\"") + "\""},
                        },
                        "options"},
                    {"iswitness", RPCArg::Type::BOOL,  "depends on heuristic tests", "Whether the transaction hex is a serialized witness transaction.\n"
                        "If iswitness is not present, heuristic tests will be used in decoding.\n"
                        "If true, only witness deserialization will be tried.\n"
                        "If false, only non-witness deserialization will be tried.\n"
                        "This boolean should reflect whether the transaction has inputs\n"
                        "(e.g. fully valid, or on-chain transactions), if known by the caller."
                    },
                },
                RPCResult{
                    RPCResult::Type::OBJ, "", "",
                    {
                        {RPCResult::Type::STR_HEX, "hex", "The resulting raw transaction (hex-encoded string)"},
                        {RPCResult::Type::STR_AMOUNT, "fee", "Fee in " + CURRENCY_UNIT + " the resulting transaction pays"},
                        {RPCResult::Type::NUM, "changepos", "The position of the added change output, or -1"},
                    }
                                },
                                RPCExamples{
                            "\nCreate a transaction with no inputs\n"