Functionality to save profile pictures

[MauriceNino]

Create a new collection of images api/ImageStore (or something like that)

• POST api/ImageStore accepts binary image data and returns the image object
• GET api/ImageStore/{id} returns the image object (as usual)
• GET api/ImageStore/{id}/img returns the image with MIME-Type image (not json)

When the user first logs in, upload the google profile picture to our database and save it into the user.