message: Issue CURRENT_TIMESTAMP Now Extraction
  Break out `now` extraction because casting to string is called
  without an active transaction. This also fixes a Windows linkage issue.
diff: @@ -149,13 +149,42 @@ struct ICUToLocalTimestamp : public ICUDateFunc {
  struct ICULocalTimestampFunc : public ICUDateFunc {
  + struct BindDataNow : public BindData {
  + explicit BindDataNow(ClientContext &context) : BindData(context) {
  + now = context.ActiveTransaction().start_timestamp;
  + }
  +
  + BindDataNow(const BindDataNow &other) : BindData(other), now(other.now) {
  + }
  +
  + bool Equals(const FunctionData &other_p) const override {
  + auto &other = (const BindDataNow &)other_p;
  + if (now != other.now) {
  + return false;
  + }
  +
  + return BindData::Equals(other_p);
  + }
  +
  + unique_ptr<FunctionData> Copy() const override {
  + return make_unique<BindDataNow>(*this);
  + }
  +
  + timestamp_t now;
  + };
  +
  + static unique_ptr<FunctionData> BindNow(ClientContext &context, ScalarFunction &bound_function,
  + vector<unique_ptr<Expression>> &arguments) {
  + return make_unique<BindDataNow>(context);
  + }
  +
  static timestamp_t GetLocalTimestamp(ExpressionState &state) {
  auto &func_expr = (BoundFunctionExpression &)state.expr;
  - auto &info = (BindData &)*func_expr.bind_info;
  + auto &info = (BindDataNow &)*func_expr.bind_info;
  CalendarPtr calendar_ptr(info.calendar->clone());
  auto calendar = calendar_ptr.get();
  - const auto now = state.GetContext().ActiveTransaction().start_timestamp;
  + const auto now = info.now;
  return ICUToLocalTimestamp::Operation(calendar, now);
  }
  @@ -168,7 +197,7 @@ struct ICULocalTimestampFunc : public ICUDateFunc {
  static void AddFunction(const string &name, ClientContext &context) {
  ScalarFunctionSet set(name);
  - set.AddFunction(ScalarFunction({}, LogicalType::TIMESTAMP, Execute, Bind));
  + set.AddFunction(ScalarFunction({}, LogicalType::TIMESTAMP, Execute, BindNow));
  CreateScalarFunctionInfo func_info(set);
  auto &catalog = Catalog::GetCatalog(context);
  @@ -188,7 +217,7 @@ struct ICULocalTimeFunc : public ICUDateFunc {
  static void AddFunction(const string &name, ClientContext &context) {
  ScalarFunctionSet set(name);
  - set.AddFunction(ScalarFunction({}, LogicalType::TIME, Execute, Bind));
  + set.AddFunction(ScalarFunction({}, LogicalType::TIME, Execute, ICULocalTimestampFunc::BindNow));
  CreateScalarFunctionInfo func_info(set);
  auto &catalog = Catalog::GetCatalog(context);
  