Multiremote support for TestLibrary

[Siolto]

Create multiple facades, depending on the amount of configured capabilities

[Siolto]

scope fn questions

valid questions. I guess we have to do a short sync to decide which way is cleaner.

[vobu]

after an ad-hoc maintainer meeting (😸), we agreed to

• move the entire test library setup into the config (wdio*.conf.*), thus
• taking out the need to .initialize({}) from the test-scope and move it into the bootstrap of wdi5
• safe-guard the existing browser.fe.initialize(config) when called at test-scope so we don't cause side effects when moved into bootstrap-scope