[Tabs] Make header pagination scroll faster

#### Feature Description

Consider the following example:
Browsing a page with 6 tabs on mobile (only 3 fit at a time).
To get to tab 6, you have to click the pagination arrow 3 times.
That's pretty slow. I would expect one click to show tabs 4, 5, 6.
You can try this on the first official [example](https://material.angular.io/components/tabs/examples) (add some tabs in StackBlitz).


#### Use Case

Making the app more convenient on mobile.

#### More info

The scrolling is handled in `_scrollHeader()` method in [paginated-tab-header.ts](https://github.com/angular/components/blob/master/src/material/tabs/paginated-tab-header.ts#L395):
_"Move the scroll distance one-third the length of the tab list's viewport."_
The simplest solution would be replacing `viewLength / 3` with `viewLength` or `viewLength * 3 / 4`.
Another option is to make this fraction configurable through an `@Input` similarly to [animationDuration](https://material.angular.io/components/tabs/api).

从 src/material/tabs/paginated-tab-header.ts 中的 _scrollHeader() 方法开始。该方法目前会将标签列表视口移动其长度的三分之一。评估所提议的滚动距离或可配置性，然后验证在官方标签示例中，点击一次分页即可显示下一组标签，包括移动端六个标签的情况。

由索引模型根据 Issue 内容生成。