Write Azure Proxies code

[m-ruiz21]

To collect data while not overloading our applications / computers we need to create Azure functions that can make the requests for us.

Namely we need to make the following requests:

GET Playlists based on given search term (/playlist-search/{query})
GET Get average playlist song features (/playlist-features/{playlist-id})

[m-ruiz21]

Finished proxy code that includes searching for playlists and retrieving features. No PR since it was the first bit of code.