[DO-971] ffmpeg recipe with requirements (!9)

Co-authored-by: aleksandr.vodyanov <aleksandr.vodyanov@avroid.tech>
Reviewed-on: https://git.avroid.tech/Conan/conan_build/pulls/9

recipes/libvpx/all/test_package/test_package.c

@@ -0,0 +1,9 @@
+#include <vpx/vpx_codec.h>
+
+#include <stdio.h>
+
+int main()
+{
+    printf("vpx version %s\n", vpx_codec_version_str());
+    return 0;
+}