feat(chips): add asterisk when required

[DeneroWatz]

Actual Behavior:

• What is the issue? * When "input", "select" etc elements have "required=true" attribute set on them, they show a "required" indicator by showing an asterisk right on label(with md-required class on label elements). The chips are inconsistent in this aspect and do no show this. Hers is the snapshot from codepen sample edited directly: Here is how it shows for normal input:

• What is the expected behavior? Show the "required" marker right on labels.

CodePen (or steps to reproduce the issue): *

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AngularJS Versions: *

• AngularJS Version:
• AngularJS Material Version:

Additional Information:

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• Browser Version: *
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[Splaktar]

Support for ng-required and required with validation was only added to chips in 1.1.9 via PR https://github.com/angular/material/pull/11225. However, there was a regression with that which is being fixed in 1.1.10.

After 1.1.10 gets stabilized and released, this is something that could be considered.