AB#38714 Set up end point for graph explorer application mode proxy

[omersayshi]

Overview

Created basic entry point for the new endpoint that will be called.
Created empty service classes for Authorization and Graph Client to be initialized for easier understanding of endpoint structure.

Testing Instructions

• Run the repo
• Set a break point in the new controller to whichever action endpoint you are testing (Ex: Line 20 for GET)
• Run the API locally
• Open postman and call the api with your choice of action with the endpoint '/graphproxy/{Add anything here}'
• Add an authorization code as a header
• Send the request
• You should see {Add anything here} as the 'all' parameter and the authorization code as the Authorization parameter

ADO: https://dev.azure.com/microsoftgarage/Intern%20GitHub/_sprints/taskboard/GI21%20-%20Graph%20Explorer/Intern%20GitHub/Y21-S/06?workitem=38714