Support interface to google drive

[Brian Lewis]

Add necessary libraries from NuGet.

Also support retrieval of an image from the project google drive, using the ImageProcessor paradigm.

[Brian Lewis]

feat(googledrive): infrastructure for google drive, get image from googledrive

Resolves #599

→ <<cset 8feed28627a1>>

[Brian Lewis]

Install the google_credentials file in assets_local to point to the sample google drive; then you can navigate to

https://localhost:44301/google/1CUdq8bGBq4DoGw63XafDRW0kqUg-iAQn

‌

to retrieve the image:

TO DO: authentication is currently ignored.

This endpoint can also be tested:

https://localhost:44301/api/googledrive/files/

As noted in the code, the googledrive controller is most likely temporary; for testing of the API.