Externalize identity provider config

[LDMGN]

Replace compile-time configuration (environment.ts) with runtime configuration (external config.js available alongside index.html and other assets). Also replace dev configuration with staging in pipeline (pipeline is not yet parameterized to switch between staging and production).

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[pschildkamp]

Don't we need an src/environments/environment.staging.ts where the production is set to true aswell? We have it for local and producion? Or do you use the *.prod.ts file for building the staging?

[LDMGN]

Don't we need an src/environments/environment.staging.ts where the production is set to true aswell? We have it for local and producion? Or do you use the *.prod.ts file for building the staging?

The latter. Because environment.ts and environment.production.ts are not about the deployment environment, but about the build. So there is a development build and a production build (which can be different regarding debug logs, minification, etc).

Then there is deployment, which can be done to staging or production. And when deploying you generally always deploy a production build. So a production build (one using environment.production.ts) will go to both staging and (when given the green flag) to production.