Introduce another way to escape mapping (other than I())

For arrayOk attributes like marker.size, using I() doesn't always do what you want because I() has dual meaning -- it says prevent mapping and also make sure it converts to JSON as an array.

For example,

plot_ly(x = 1:40, y = 1:40, size = I(30))

Perhaps we could export a function, like i() or something, that prevents mappings, but doesn't add the "AsIs" class.

まず、marker.size のような arrayOk 属性を使った plot_ly の例を再現し、次に I() がマッピングを防ぎ、AsIs クラスを追加する仕組みを追跡します。エクスポートされた代替手段が AsIs を追加せずにマッピングを防ぎ、I() が既存の二重の動作を維持すれば、変更は完了です。