fix: apply font-family to text components

[devversion]

• Applies the font-family to all components that use content projection and have a label or a text displayed.
• Switches the hard-coded font-family in the simple-snack-bar to the global variable.

Notes:

• All families have been applied to the host elements (to simplify font overwriting)
• The dialog font family has been skipped here. Not sure whether we want that for the users instantiated component (I'd only say md-dialog-content etc. directives)

References #2750

[jelbourn]

LGTM, though we may revisit once we work on a more comprehensive typography approach

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