Provide Automatic Binding of FormControl Error Messages and Status to input hints

#### Bug, feature request, or proposal:
This is a feature request.

This is related to #348, but is specifically asking for the material guidance to be a part of the framework, integrating with standard functionality of @angular/forms.

#### What is the expected behavior?

Looking at [Material Error Patterns](https://material.io/guidelines/patterns/errors.html), there seems to be a standard behavior of inlining form error message into the hint area (with a specific color).

It also supports separating the existing hint from the error message via a comma.

#### What is the current behavior?
Error state and messages are not handled.

#### What are the steps to reproduce?
There is nothing to show as this is feature that is yet to be implemented. [Material Error Patterns](https://material.io/guidelines/patterns/errors.html) should provide the expected behavior and visual treatment.

#### What is the use-case or motivation for changing an existing behavior?
The general gist is that if everyone were to follow the guidelines from material.io, you would end up with a fair amount of duplicate code for every input. The pervasiveness of the desired functionality seems like a prime candidate for handling at the framework level.

#### Which versions of Angular, Material, OS, browsers are affected?
All

#### Is there anything else we should know?

Inizia con il riferimento Material Error Patterns e l’integrazione di @angular/forms di Angular descritta nell’issue. Poiché non è indicato alcun file o test, identifica i punti di ingresso del framework e definisci la copertura per la visualizzazione automatica di errori/stato, la separazione degli hint e il trattamento visivo richiesto; il lavoro è completato quando il comportamento viene fornito a livello di framework invece di essere duplicato per ogni campo di input.

Scritto dal modello di indicizzazione a partire dal testo della issue.