Reverting 'Merge pull request #2483 python-history-provider'

We didn't experience the expected performance improvements. Locally under
unit test there was aboout an order of magnitude throughput increase, but
when run against the history benchmark, this new approach was 60% slower.
We're reverting this for now to perform further analysis and better
understand the performance profiling of the python history stack.

Algorithm.Python/UpdateOrderRegressionAlgorithm.py

@@ -14,16 +14,17 @@
 from clr import AddReference
 AddReference("System.Core")
 AddReference("System.Collections")
+AddReference("QuantConnect.Algorithm")
 AddReference("QuantConnect.Common")
 
 from System import *
 from System.Linq import *
 from QuantConnect import *
+from QuantConnect.Algorithm import *
 from QuantConnect.Data import *
 from QuantConnect.Orders import *
 from QuantConnect.Securities import *
 from QuantConnect.Util import *
-from QCAlgorithm import QCAlgorithm
 import decimal as d
 from math import copysign
 from datetime import datetime