Use @types/dkfds and import "dkfds" statically in Tooltip and DatePicker

[chcederquist]

DKFDS is currently being imported and placed on the window object, and is not type-safe.
DefinitelyTyped has types for DKFDS now, and it should be possible to import it through a static import declaration.

Problematic components here:
https://github.com/search?q=repo%3Achcederquist%2Freact-dkfds+const+dkfds+%3D+import%28%22dkfds%22%29%3B&type=code

DefinitelyTyped types and sample usage here: https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/dkfds