Make local debugging of Angular app possible

[brio1009]

This is a follow-up PR to #57 and should only be reviewed and merged after that one.

This PR mostly adapts some configuration files to ensure that bringing up local debugging servers with hot-reload is possible so local debugging of the typescript code is possible. There is one change in server.js to prevent serving of the built Angular app in development mode so that the hot-reloaded ng serve variant can be used. I took care that this change does not affect the production behavior of server.js.