movie: Add clock init time to CTM header

This adds a clock init time field to the CTM header. The clock settings would be overridden when playing a movie. And when recording a movie, if the clock is set to System Time, it would be set to fixed init time at the current moment as well. In this way this keeps consistency with the RNG even if the user does just no setting.

src/core/movie.h

@@ -44,7 +44,17 @@ public:
     void StartPlayback(const std::string& movie_file,
                        std::function<void()> completion_callback = {});
     void StartRecording(const std::string& movie_file);
+
+    /// Prepare to override the clock before playing back movies
+    void PrepareForPlayback(const std::string& movie_file);
+
+    /// Prepare to override the clock before recording movies
+    void PrepareForRecording();
+
     ValidationResult ValidateMovie(const std::string& movie_file, u64 program_id = 0) const;
+
+    /// Get the init time that would override the one in the settings
+    u64 GetOverrideInitTime() const;
     u64 GetMovieProgramID(const std::string& movie_file) const;
 
     void Shutdown();
@@ -119,6 +129,7 @@ private:
     PlayMode play_mode;
     std::string record_movie_file;
     std::vector<u8> recorded_input;
+    u64 init_time;
     std::function<void()> playback_completion_callback;
     std::size_t current_byte = 0;
 };