Creating a CodeRefactoringProvider to refactor source code to recommend using C# 7.0 tuples

Code refactoring providers are IDE extensions to refactor source code for better code structuring, without affecting the functional or semantic behavior of the code. These are built on top of Roslyn's Workspaces layer and operate on the current document being edited. When a user invokes a command such as Ctrl + dot in Visual Studio editor, the IDE code refactoring engine computes all the refactorings that can refactor the code in the currently selected text span in the editor. Each of these providers are then invoked with a code refactoring context containing the current document and span. Refactorings operate on the underlying syntax tree associated with the document by adding, removing, or editing the syntax nodes within the tree and returning the new document with the refactored code. They might also alter the contents of the containing project or solution. When the user commits the refactoring...