Supports new-style primary key options
Supports new-style primary key options

rails/rails#39365 introduced new-style id options like the followings.

```
// < 6.1 old-style
create_table(:items, id: :bigint, unsigned: true) {}

// >= 6.1 new-style
create_table(:items, id: { type: :bigint, unsigned: true }) {}
```

To compare those styles to get diff, I handled that I normalizes id options
from those styles.

winebarrel/ridgepole