Fixes #53466

Fixes #59151

* make actionbar support different trigger keys

* add some undefined checks

Dispose of webviews after each test run

Added actions from #57321 to the 'No Settings Found'-message

Multiple repls per debug session

The previous solution involved an own solution with an array of
disposables. The new solution makes use of the _register-method from the
Displosable class.

Fixes for 58176: Middle clicking files in breadcrumbs explorer opens …

#53989

[CSS fix] Settings tab alignment