needsListConversion function
Checks if a type is a List<T> where T is not a primitive.
Implementation
bool needsListConversion(String type) {
final bt = baseType(type);
if (!bt.startsWith('List<')) return false;
final inner = bt.substring(5, bt.length - 1);
return !const [
'String',
'int',
'double',
'bool',
'num',
'dynamic',
].contains(inner);
}