Remove spec-compliant reference picture list init and modification.

Turns out these parts don't need to be done exactly according to the
spec. The vulkan docs are not very clear on this unfortunately, but
it seems to work.

vk-video/src/parser.rs

@@ -21,8 +21,7 @@ mod reference_manager;
 #[derivative(Debug)]
 #[allow(non_snake_case)]
 pub struct DecodeInformation {
-    pub(crate) reference_list_l0: Option<Vec<ReferencePictureInfo>>,
-    pub(crate) reference_list_l1: Option<Vec<ReferencePictureInfo>>,
+    pub(crate) reference_list: Option<Vec<ReferencePictureInfo>>,
     #[derivative(Debug = "ignore")]
     pub(crate) rbsp_bytes: Vec<u8>,
     pub(crate) slice_indices: Vec<usize>,