Fixes #100536

These commands currently do not work because:

- The use the `hasFocus` check in layout.ts
- This looks at the active element and checks if the active element has a parent in the editor dom
- However webviews are outside of the normal dom flow (since they cannot be reparented without being destroyred)

To fix this, this PR adds allows dom node to point to their explicit parent using `setParentFlowTo`. Instead of a normal ancestor check, we then check ancestors while observing the flow to parents of node

The webview element is then update to have a parent flow to that points at its editor node

Ref #109967

Fix composition logic for Firefox

cc @jrieken

* disable submenus rendered as dropdowns
fix #109305

* address comments

Fix #107858

Fixes #93403

Part of https://github.com/microsoft/vscode/issues/93864

Fixes #97467

Fixes #90005

Fixes https://github.com/microsoft/vscode/issues/109251

fixes #110009

Fixes https://github.com/github/codespaces/issues/1695 and fixes microsoft/vscode-remote-release#2536