Reimplemented explain feature

src/core/sheerka/services/SheerkaHistoryManager.py

@@ -11,6 +11,7 @@ class History:
         self.event = event
         self.result = result
         self._status = None
+        self._format_instructions = None
 
     def __str__(self):
         msg = f"{self.event.get_digest()} {self.event.date.strftime('%d/%m/%Y %H:%M:%S')} : {self.event.message}"
@@ -42,6 +43,12 @@ class History:
         self._status = self.result.get_status() if self.result else None
         return self._status
 
+    def get_format_instructions(self):
+        return self._format_instructions
+
+    def set_format_instructions(self, instructions):
+        self._format_instructions = instructions
+
 
 class SheerkaHistoryManager(BaseService):
     NAME = "History"