Motivation for changes:

Main motivation was to enable multiple image types since original size is too big for UI.

Detailed changes:

• Made posters and backdrops lazy and independent of movie request
• Caching of tmdb_config to DB to reduce number of calls
• API now return an array of URLs in all available sizes instead of just original size (sizes are dynamically loaded from tmdb api).

To Do:

• Adjust UI to the changes (@Tommatheussen)