C#: Delete deprecated data flow api.

Author: aschackmull

csharp/ql/lib/semmle/code/csharp/dataflow/DataFlow.qll

@@ -9,5 +9,5 @@ module DataFlow {
   private import semmle.code.csharp.dataflow.internal.DataFlowImplSpecific
   private import codeql.dataflow.DataFlow
   import DataFlowMake<Location, CsharpDataFlow>
-  import semmle.code.csharp.dataflow.internal.DataFlowImpl1
+  import Public
 }

csharp/ql/lib/semmle/code/csharp/dataflow/DataFlow2.qll

@@ -6,10 +6,9 @@
 import csharp
 
 module TaintTracking {
-  import semmle.code.csharp.dataflow.internal.tainttracking1.TaintTrackingParameter::Public
+  import semmle.code.csharp.dataflow.internal.TaintTrackingPublic
   private import semmle.code.csharp.dataflow.internal.DataFlowImplSpecific
   private import semmle.code.csharp.dataflow.internal.TaintTrackingImplSpecific
   private import codeql.dataflow.TaintTracking
   import TaintFlowMake<Location, CsharpDataFlow, CsharpTaintTracking>
-  import semmle.code.csharp.dataflow.internal.tainttracking1.TaintTrackingImpl
 }