codec/h264/h264dec/cavlc.go: write fuzzer test for parseLevelPrefix

[Saxon Milton]

We wish to investigate the validity of testing by fuzzing over a trusted C version of the functionality in order to get expected output given a particular input. For each input the output from the C code will be captured, then the input will be given to the go code and the outputs will be compared. We will start with some simple functionality, namely the parsing process for level prefix in the cavlc stuff.

‌

[Saxon Milton]

Efforts towards H.264 decoder have been put on hold.