`INTERVAL '1 hour'` should be equivalent to `INTERVAL 1 HOUR`

**Use case**
People are used to Postgres.
while (transformers_p.parse(pos, transformer, expected))
    {
        res->children.push_back(transformer);
    }
    node = std::move(res);
    return true;
}
bool ParserColumnsTransformers::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserKeyword apply("APPLY");
    ParserKeyword except("EXCEPT");
    ParserKeyword replace("REPLACE");
    ParserKeyword as("AS");
    if (apply.ignore(pos, expected))
    {
        if (pos->type != TokenType::OpeningRoundBracket)
            return false;
        ++pos;
        String func_name;
        if (!parseIdentifierOrStringLiteral(pos, expected, func_name))
            return false;
        if (pos->type != TokenType::ClosingRoundBracket)
            return false;
        ++pos;
        auto res = std::make_shared<ASTColumnsApplyTransformer>();
        res->func_name = func_name;
        node = std::move(res);
        return true;
    }
    else if (except.ignore(pos, expected))