scripted-diff: Rename ValidAsCString to ContainsNoNUL

-BEGIN VERIFY SCRIPT-
 sed -i 's,ValidAsCString,ContainsNoNUL,g' $(git grep -l ValidAsCString)
-END VERIFY SCRIPT-

src/util/moneystr.cpp

@@ -40,7 +40,7 @@ std::string FormatMoney(const CAmount n)
 
 std::optional<CAmount> ParseMoney(const std::string& money_string)
 {
-    if (!ValidAsCString(money_string)) {
+    if (!ContainsNoNUL(money_string)) {
         return std::nullopt;
     }
     const std::string str = TrimString(money_string);