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

**Use case**
People are used to Postgres.
if (trim_left && trim_right)
        {
            func_name = "trimBoth";
        }
        else
        {
            if (trim_left)
            {
                func_name = "trimLeft";
            }
            else
            {
                
                func_name = "trimRight";
            }
        }
    }
    auto expr_list_args = std::make_shared<ASTExpressionList>();
    if (char_override)
        expr_list_args->children = {expr_node, pattern_node, std::make_shared<ASTLiteral>("")};
    else
        expr_list_args->children = {expr_node};
    auto func_node = std::make_shared<ASTFunction>();
    func_node->name = func_name;
    func_node->arguments = std::move(expr_list_args);
    func_node->children.push_back(func_node->arguments);
    node = std::move(func_node);
    return true;
}
bool ParserLeftExpression::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)