disable horizontal scroll in virtual scroller

#### Please describe the feature you would like to request.
I would like an input for `cdk-virtual-scroll-viewport` directive which disabled the horizontal scroll, or in other words sets the width of `cdk-virtual-scroll-content-wrapper` to 100%, as opposed to just setting the min-width by default, to enable horizontal scrolling.

#### What is the use-case or motivation for this proposal?
Sometimes you have long list values and you want them to fit the width of your list and be displayed with ellipses, as opposed to having horizontal scroll. Because of how this component is implemented, putting the `min-width: 100%` in `cdk-virtual-scroll-content-wrapper` prevents me from limiting the width of the items by the parent's width.

#### Is there anything else we should know?
No.

issue に記載されている cdk-virtual-scroll-viewport ディレクティブと cdk-virtual-scroll-content-wrapper のスタイリングから始めます。wrapper が現在どのように最小幅を適用しているかを追跡し、横スクロールを防ぐために必要な input の動作を特定します。長いリスト値が親の幅に収まり、横スクロールなしで省略記号を表示できれば完了です。

索引モデルが issue の本文から書いたものです。