Develop & Finalize UserDAO Structure

[StruckCroissant]

Need to develop the following endpoints for user table integrations:

• [x] add user
• [x] get all users
• [x] get user by id
• [x] delete user by id
• [x] update user
• [ ] get user's played games
• [ ] get user's liked games
• [ ] get user's favorite genres
• [ ] get recommended games

Note: Favorite genres endpoint is not well-defined. This could be implemented by grabbing information via the genres attached to a user's liked games.