message: refactor: Change pointer to reference because it can not be null
diff: @@ -189,7 +189,7 @@ static std::string LabelFromValue(const UniValue& value)
  /**
  * Update coin control with fee estimation based on the given parameters
  *
  - * @param[in] pwallet Wallet pointer
  + * @param[in] wallet Wallet reference
  * @param[in,out] cc Coin control to be updated
  * @param[in] conf_target UniValue integer; confirmation target in blocks, values between 1 and 1008 are valid per policy/fees.h;
  * if a fee_rate is present, 0 is allowed here as a no-op positional placeholder
  @@ -201,7 +201,7 @@ static std::string LabelFromValue(const UniValue& value)
  * verify only that fee_rate is greater than 0
  * @throws a JSONRPCError if conf_target, estimate_mode, or fee_rate contain invalid values or are in conflict
  */
  -static void SetFeeEstimateMode(const CWallet* pwallet, CCoinControl& cc, const UniValue& conf_target, const UniValue& estimate_mode, const UniValue& fee_rate, bool override_min_fee)
  +static void SetFeeEstimateMode(const CWallet& wallet, CCoinControl& cc, const UniValue& conf_target, const UniValue& estimate_mode, const UniValue& fee_rate, bool override_min_fee)
  {
  if (!fee_rate.isNull()) {
  if (!conf_target.isNull() && conf_target.get_int() > 0) {
  @@ -220,7 +220,7 @@ static void SetFeeEstimateMode(const CWallet* pwallet, CCoinControl& cc, const U
  throw JSONRPCError(RPC_INVALID_PARAMETER, InvalidEstimateModeErrorMessage());
  }
  if (!conf_target.isNull()) {
  - cc.m_confirm_target = ParseConfirmTarget(conf_target, pwallet->chain().estimateMaxBlocks());
  + cc.m_confirm_target = ParseConfirmTarget(conf_target, wallet.chain().estimateMaxBlocks());
  }
  }
  @@ -495,7 +495,7 @@ static RPCHelpMan sendtoaddress()
  coin_control.m_avoid_address_reuse = GetAvoidReuseFlag(pwallet, request.params[8]);
  // We also enable partial spend avoidance if reuse avoidance is set.
  coin_control.m_avoid_partial_spends |= coin_control.m_avoid_address_reuse;
  - SetFeeEstimateMode(pwallet, coin_control, /* conf_target */ request.params[6], /* estimate_mode */ request.params[7], /* fee_rate */ request.params[9], /* override_min_fee */ false);
  + SetFeeEstimateMode(*pwallet, coin_control, /* conf_target */ request.params[6], /* estimate_mode */ request.params[7], /* fee_rate */ request.params[9], /* override_min_fee */ false);
  EnsureWalletIsUnlocked(pwallet);
  