[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/mpg123/all/test_package/test_package.c

@@ -0,0 +1,12 @@
+#include "mpg123.h"
+#include <stdio.h>
+
+int main() {
+    int error;
+    mpg123_pars *pars;
+
+    pars = mpg123_new_pars(&error);
+    mpg123_fmt_all(pars);
+    mpg123_delete_pars(pars);
+    return 0;
+}