**Describe the issue**

```
github-explorer.ru-central1.internal :) ALTER TABLE hackernews MODIFY COLUMN text CODEC(ZSTD), MODIFY COLUMN title CODEC(ZSTD), MODIFY COLUMN url CODEC(ZSTD)

ALTER TABLE hackernews
    MODIFY COLUMN `text` CODEC(ZSTD),     MODIFY COLUMN `title` CODEC(ZSTD),     MODIFY COLUMN `url` CODEC(ZSTD)
```

See that weird indentation without newlines?
#include <Parsers/ASTAlterQuery.h>
#include <IO/Operators.h>
#include <iomanip>
#include <Common/quoteString.h>
namespace DB
{
namespace ErrorCodes
{
    extern const int UNEXPECTED_AST_STRUCTURE;
}
ASTPtr ASTAlterCommand::clone() const
{
    auto res = std::make_shared<ASTAlterCommand>(*this);
    res->children.clear();
    if (col_decl)
    {
        res->col_decl = col_decl->clone();
        res->children.push_back(res->col_decl);
    }
    if (column)
    {
        res->column = column->clone();
        res->children.push_back(res->column);
    }
    if (order_by)
    {
        res->order_by = order_by->clone();
        res->children.push_back(res->order_by);
    }