* wip 2

* use viewlet stubs

* fix layering issue

* fix saveState and contextmenus

* move context menu logic into panecomposite

* revert tasks.json

* tasks again

* add showHeaderInTitleWhenSingleView values

* patch tests

* some cleanup

* more cleanup

* start view

* merging conflicts

* fix title and dnd

* adding missing api surface to pane composite

* additional merge resolution

* rename splitview panels to panes

* rename files

* customViewPane

cange condition on outline tree refiltering to bring it in line with new OutlineFilter implementation

Emitters should generally not be reassigned as their corresponding event would also be lost. Marking these as readonly just to enforce this

related to microsoft/TypeScript#32526

The panel currently exposes a `disposables` protected member. In order to catch possible leaks of disposables, we should extend `Disposable` instead

See issue in the original repo: https://github.com/Microsoft/vscode/issues/73213

related to #67876