prefix test names with libva_

> The binary names could all be prefixed with libva or something like that. Ideally this would be fixed upstream first.

```
+/usr/bin/av1encode
+/usr/bin/avcenc
+/usr/bin/avcstreamoutdemo
+/usr/bin/h264encode
+/usr/bin/hevcencode
+/usr/bin/jpegenc
+/usr/bin/loadjpeg
+/usr/bin/mpeg2vaenc
+/usr/bin/mpeg2vldemo
+/usr/bin/putsurface
+/usr/bin/putsurface_wayland
+/usr/bin/sfcsample
+/usr/bin/vacopy
+/usr/bin/vavpp
+/usr/bin/vp8enc
+/usr/bin/vp9enc
+/usr/bin/vpp3dlut
+/usr/bin/vppblending
+/usr/bin/vppchromasitting
+/usr/bin/vppdenoise
+/usr/bin/vpphdr_tm
+/usr/bin/vppscaling_csc
+/usr/bin/vppscaling_n_out_usrptr
+/usr/bin/vppsharpness
```

I was talking about including tests inside the package, but these names are pretty generic, would be ok to prefix them with `libva_` ?