Refactor BatteryModel and market handling for improved time tracking, logging, and market rate calculations

Something is slow, I suspect its the logging, but time is tight, so I'm going to wrap up to make it at least useable

src/batterymodel/models/battery.py

@@ -110,7 +110,8 @@ class BatteryModel:
                                   self._current_charge_value)
 
     def log_state_change(self, fn, original_state, new_state):
-        self._decision_log_handle.write(f"{self.current_time},{self._runtime},{fn},{original_state},{new_state}\n")
+        # self._decision_log_handle.write(f"{self.current_time},{self._runtime},{fn},{original_state},{new_state}\n")
+        pass
 
     def handle_storage_capacity_check(self, previous_state: "BatteryModel"):
         if self._charge_discharge_cycles > previous_state._charge_discharge_cycles and self._charge_discharge_cycles / int(self._charge_discharge_cycles) == 1:

src/batterymodel/models/market.py

@@ -42,7 +42,7 @@ class MarketState:
             elif last_timestamp is not None and last_timestamp < key and key_delta > delta:
                 return last_timestamp, self._market_data[last_timestamp]
             else:
-                                                       last_timestamp = key
+                last_timestamp = key
         return None