Models Refactoring: Move methods to roles

app/models/event.rb

app/models/event/push_trait.rb

app/models/issue.rb

app/models/key.rb

app/models/merge_request.rb

app/models/project.rb

app/models/project/hooks_trait.rb

app/models/project/permissions_trait.rb

app/models/project/repository_trait.rb

app/models/project/validations_trait.rb

app/models/user.rb

app/roles/account.rb

app/roles/authority.rb

app/roles/git_merge.rb

app/roles/git_push.rb

app/roles/push_event.rb

app/roles/repository.rb

app/roles/ssh_key.rb

app/roles/team.rb

app/roles/upvote.rb