Make CI fail when warnings in console

[PVince81]

We should trigger a CI failure whenever we detect warnings in the browser console at the end of any successful test.

If this is too complicated to do technically, then at least add scenarios for the main pages like the files app, public link page and files drop.

This way we can catch these earlier as they could be signs of regressions.

@individual-it @DeepDiver1975 @LukasHirt

[PVince81]

Context: we had ODS updates recently that introduced new required attributes but CI still passed.
Ref to a PR of mine that fixes this kind of warnings: #2727

[PVince81]

I found this API to access log entries: https://stackoverflow.com/a/53780970

[individual-it]

we could have a check in the AfterScenario hook

[PVince81]

I managed to come up with something that works: #2729

[pascalwengerter]

We should take another look at this after #5194 got merged

[pascalwengerter]

Closing as not relevant anymore. We usually check the console for warnings&errors when doing PR reviews and releases

Also @ScharfViktor maybe take note of this idea for improving smoke tests in the future. Not pressing from my POV, though