[Part 3] Create convenience constructor for the listed Transforms.

[zeahmed]

This work item is related to #371 and is the 3rd work item in series of creating convenience constructor (cf. #380 and #487). In this work item, convenience constructors will be created following set of transforms.

• GroupTransform.cs
• HashJoinTransform.cs
• KeyToBinaryVectorTransform.cs
• LoadTransform.cs
• MissingValueIndicatorTransform.cs
• MutualInformationFeatureSelectionTransform.cs
• NADropTransform.cs
• NAHandleTransform.cs
• NAIndicatorTransform.cs
• NAReplaceTransform.cs
• OptionalColumnTransform.cs
• RffTransform.cs
• UngroupTransform.cs
• WhiteningTransform.cs