Changing to read_async allows for async reading of the poster image
Adding try/except for slider function

Adding spinner to show query running
Refactored Search to call results directly (vs in main loop) (helped with threading simplification)

Mouse events to hide/show controls
Organizing flowbox list (children) to show/hide on fullscreen
App is still synchronous (initial threading attempt throws errors),

Switching to flowbox, removing excess gtkboxes, connected button signals, standardized on default gtk styling (mostly)