Migrate to Angular 11

[superole]

I upgraded the m5/angular-cli-app/start/frontend to Angular version 11, one major-version at a time, including peer-dependents.

I realize that upgrading only one app in one module of course-related code is not immensely useful, but I wanted to redo the exercise with Angular 11, and since I spent some time on the upgrade I felt like sharing it.