feat(core): directive to add extra classes to components for m1 compat

[jelbourn]

See #1479

I don't like the name "Compatibility" but I don't have any better ideas.

I had originally been thinking we'd have to add the class in the constructor for each individual components, but this approach is much cleaner.

[kara]

StyleCompatibilityModule?

[jelbourn]

Good to merge if CI is green

[jelbourn]

Nope, problem with md-menu (which already has an md-menu class).

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