Create default profile images

[ModeratelyGreek]

Right now, profile pictures do not exist. We want to be able to provide our members with a default profile pic that also uniquely identifies them, not unlike Discord's random color:

OR github's pixel designs:

Approaches:
Foremost, we need the user to be able to provide a profile picture at all, to replace the default we generate. This will become a URL tied to the user object and probably pointing to an S3 bucket object.

For generating their image, there's two main paths:

1. Generate --> Save as if its a normal image (to the S3 bucket, use the URL, etc)
2. Display generated image from ID hash if no image provided

The latter option, hashing, is what github uses. See more info here.