Int-Tests: use memfs instead of fs

Fixes #78180

This way it goes through the absolute and relative checks

Fixes #78206

Redo emmet change. Fix #70371

Fixes #78157

Use correct resolved TDO and task for custom execution

* List possible categories

* TODO comment

* Message if category is invalid

Up until very recently, the custom tree used a TreeResourceNavigator2 with openOnSelection: true. This caused command to be executed twice on clicks though. Once on the selection and once on the click. Setting that to false caused the enter key to stop causing commands to run though. This was because the enter key was only causing the selection to trigger, not the open. The Open event was getting swallowed before it made it out of the tree because it was missing a UIEvent. Adding the UIEvent in here fixes that

Fixes #78174

Renames ${qs} to ${query}

by fixing the tree width, which was not being set

Fixes #78177

Fixes #78178