Blur backdrop in detail view (no performance issues)

This adds a blur (and slight contrast and brightness) to the backdrops in the movie details view. While this, in my opinion, looks better than the current look it's mostly a POC.
A comment in the scss said blurs were terribly slow, on my machine at least it's not? Might be the added 3d translation? Anyways, merge if you like it, peek at it for future reference.