VC-2 decoder Vulkan Implementation

This projects's aim is to implement the VC-2 decoder for FFmpeg in vulkan. VC-2 is a low-latency video codec that uses wavelet transforms and entropy coding. It can be readily implemented in hardware or software at very high bit rates. It can also be efficiently implmented on GPU hardware. To this, end, an encoder and a decoder must be implemented and tested with the VC-2 conformance software. The encoder requires a wavelet transform, quantization, etropy coding and writing back the result in a proper format and bitstream coding. The decoder, in turn, reuires: bitstream parsing, entropy decoding, dequantization and another wavelet transform.