Follow cursor does not expand subtree

[octref]

Testing #69299.

• Have this following scss file:

.bar {
  .baz {

  }
}

• Have .bar collapsed.
• Move cursor between .baz
• Tree won't expand until you click it

This works in stable.

[joaomoreno]

@roblourens With this change, when you call reveal on a tree item which is in the model but not in the view, I take care of expanding its ancestor path, so you should be able to remove stuff like https://github.com/Microsoft/vscode/blob/877f19187d7c0a3f31367332067182a6d0a0d4f8/src/vs/workbench/contrib/preferences/electron-browser/settingsEditor2.ts#L697

@isidorn Still not there for the async trees, but getting close!

[joaomoreno]

Fixed by d810435