Optimize the code

1. change param_strs to params
2. move params from MediaInfo to MediaTuple
3. passing MediaTuple as a parameter for some functions

src/Common/MediaSource.h

@@ -299,7 +299,6 @@ public:
     std::string full_url;
     std::string schema;
     std::string host;
-    std::string param_strs;
 };
 
 bool equalMediaTuple(const MediaTuple& a, const MediaTuple& b);