feat(Tabs): Tab list should be scrollable to match Material Design Guidelines

#### Reproduction

https://stackblitz.com/edit/angular-yk3xrb

Steps to reproduce:
1. Load above stackblitz in mobile view.
2. Try to grab and swipe the tabs left or right.
* Alternatively use `Shift` + `Mouse Scroll` to attempt to scroll the tabs left/right.

#### Expected Behavior

The tabs should be x-scrollable as defined in the spec: https://material.io/components/tabs (Switch from `Fixed` to `Scrollable` type)

#### Actual Behavior

Tabs can not be scrolled by swiping/shift scrolling.

This is mainly a big issue for mobile devices. As tapping the left and right buttons is much slower and unnatural than swiping over the tabs.
You can manually set `overflow-x: scroll` on the container, but that breaks as soon as you select another tab since angular applies translation to the whole thing. See [this stackoverflow ](https://stackoverflow.com/questions/57888846/set-horizontal-scroll-in-angular-material-tabs) for attempts at solving the issue.

Start with the linked StackBlitz reproduction and compare the current tabs behavior with the Material Design tabs specification. Trace the Angular Material tabs implementation responsible for tab scrolling and translation, then verify that mobile swiping and Shift-plus-mouse-wheel scrolling work without breaking selection or positioning.

Written by the indexing model from the issue text.