make mat-step-header header scrollable

#### Please describe the feature you would like to request.
I would like to see the mat-step-header made scrollable in a similar fashion to mat-tab. IOf you have multiple steps on a smaller resolution or inside a container with a specific width the steps simply overflow over the edge and would be better if you have a left/right scroll button on either side of the header like the mat-tab

#### What is the use-case or motivation for this proposal?
I have several apps that use the material stepper (specifically the horizontal stepper) where there are many steps in the flow, the stepper is usually displayed inside a mat-card with a specific width (responsive to difference screen sizes)

On smaller screen sizes where there are more steps than permitted on the screen the step headers simply overflow off the screen

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

This is a screen shot of one example on a large mobile (width: 425px)

Inizia confrontando il comportamento di horizontal mat-step-header con quello dell’header mat-tab scorrevole, concentrandoti su come ciascuno gestisce molti elementi in un contenitore stretto. Conferma il comportamento previsto per lo screenshot mobile e considera completato il lavoro quando viene impedito l’overflow degli header degli step, fornendo al contempo controlli di scorrimento utilizzabili verso sinistra e verso destra.

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