Bug: Proxy handling is not correct

[wurzelkuchen]

Quick Description

We currently have some issues with proxies.

1. External Proxies with authentication do not work right now, this need to be fixed
2. We try to open local proxies even if we are working in a remote environment like browserstack, this will lead to unpredictable errors, and needs to be fixed.

Tasks

• Make an overview on all kinds of proxies we support, how they work, how they are configured and how this is documented
• Fix proxy authentication for external proxies
• Throw an error if someone has configured a local proxy in combination with an external environment.

Actual Behaviour

Proxies do not work as expected.

Expected Behaviour

Proxies should work as expected ;)