GetLastKnownPrices python data (#6191)

* Adding unit tests reproducing issue.

* Fix a couple of minor bugs

- IsMarketOpen will work correctly when used with daily and hourly
  resolution.
- slice.Get will work correctly with python custom data
- ExtendedDictionary will be able to dinamically access methods,
  required for python and private C# data types

* Refactor solution. Add more tests

* Remove unrequired import statement

Algorithm.Python/BasicTemplateOptionsHourlyAlgorithm.py

@@ -57,7 +57,7 @@ class BasicTemplateOptionsHourlyAlgorithm(QCAlgorithm):
             key = lambda x: x.Right, reverse=True)
 
         # if found, trade it
-        if len(contracts) == 0: return
+        if len(contracts) == 0 or not self.IsMarketOpen(contracts[0].Symbol): return
         symbol = contracts[0].Symbol
         self.MarketOrder(symbol, 1)
         self.MarketOnCloseOrder(symbol, -1)