Add missing start_time to python API (#591)

Co-authored-by: vsd-vector <askars.salimbajevs@tilde.lv>

@@ -24,6 +24,9 @@ static void PybindOnlineRecognizerResult(py::module *m) {
           "tokens",
           [](PyClass &self) -> std::vector<std::string> { return self.tokens; })
       .def_property_readonly(
+          "start_time",
+          [](PyClass &self) -> float { return self.start_time; })
+      .def_property_readonly(
           "timestamps",
           [](PyClass &self) -> std::vector<float> { return self.timestamps; });
 }

@@ -509,6 +509,9 @@ class OnlineRecognizer(object):
     def timestamps(self, s: OnlineStream) -> List[float]:
         return self.recognizer.get_result(s).timestamps
 
+    def start_time(self, s: OnlineStream) -> float:
+        return self.recognizer.get_result(s).start_time
+
     def is_endpoint(self, s: OnlineStream) -> bool:
         return self.recognizer.is_endpoint(s)