Changing endpoint access and cleaning up gameAdsList

[MiamiYukiYuri]

• [x] Delete gameAdsList in GameAdsModel, configure randomizer method in GameAdsService
• [x] Delete methods for creating a user, since that happens with the sign up process

Edit endpoint access for role user according to Helenas comments

• [x] Make sure that a user only has access to orders connected to that specific user
• [x] Make sure that a user is the only one who has access to see user details such as address, email etc.