[Backend] - Public/Private Ownership - Central UI Changes

[drewjhart]

Background:

After discussing with the team (captured in the wiki here), we have decided to implement separate tables for Public and Private GameTemplates and QuestionTemplates. This PR and the following one implement that strategy.

They break down per:
[Backend] - Public/Private Ownership #1082
-> [Backend] - Public/Private Ownership - Central UI Changes #1096
->-> [Backend] - Public/Private - Bug Fixes #1101

The preceding PR (#1082) is focused around networking changes that provide the required updates to the schema.graphql and the associated APIClients. This PR (#1096) is focused around UI updates to ensure that central is functional. The following PR (#1101) cleans up some bugs.

Note: central is currently undergoing a redesign. As such, these changes are implemented as easily as possible with limited changes to the codebase. We're going to need to rewrite central so I'm just adding in UI changes that are required to get the Public/Private setup off the ground

Updates:

The following UI updates are required to handle the new Public/Private set up:

1. Pass owner information to Game/Question Card so that it "Created By: " can be displayed in the Public Games section
2. Update edit, clone, delete functions on Game/Question Card so that they are limited for owner etc
3. Add Public/Private radio buttons on drop down to filter query results accordingly.
4. Add Public/Private radio buttons on GameTemplate and QuestionTemplate creation. Disable these buttons when adding questions to games, etc, so that public games and public questions are always related, and vice-versa
5. Update signup screen to use username (this allows the username to get added to the owner field, instead of more sensitive email)