TODOs which aren't blocked anymore

[ghost]

Looking through the code, you will find some TODOs which wait for an issue to be resolved.
I think it would be good to have an issue to list TODOs which can be solved because the blocking issue got resolved.

• shared/models/users/user-role.ts

  // TODO: use UserRole for key once Enums can not be used for index signature types microsoft/TypeScript#13042 is fixed

• server/controllers/api/users/index.ts

  // TODO: Once Change the position of the user menu inside the sidebar #289 is merged, implement revoke token route

• client/src/main.ts

  // TODO: Remove when Existing App does not get Service Worker capabilities angular/angular-cli#8779 is fixed?