**Use case**
`SELECT POSITION('/' IN s) FROM (SELECT 'Hello/World' AS s);`

The same as `position(s, '/')`

{
    if (pos->type != TokenType::StringLiteral)
        return false;
    String s;
    ReadBufferFromMemory in(pos->begin, pos->size());
    try
    {
        readQuotedStringWithSQLStyle(s, in);
    }
    catch (const Exception &)
    {
        expected.add(pos, "string literal");
        return false;
    }
    if (in.count() != pos->size())
    {
        expected.add(pos, "string literal");
        return false;
    }
    auto literal = std::make_shared<ASTLiteral>(s);
    literal->begin = pos;
    literal->end = ++pos;
    node = literal;
    return true;
}
template <typename Collection>
bool ParserCollectionOfLiterals<Collection>::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)