Defterm commandline applications aren't under the WindowsTerminal process tree - maybe they should be?

1. set up defterm
2. run cmd.exe
3. see the following:


There's a `OpenConsole -Embedding` and a `WindowsTerminal -Embedding` that are started, but the `cmd` that is started is not parented to those - it's sitting as a child of explorer, and it still owns the system conhost that did the handoff.

We may need to somehow reparent the cmd.exe & it's conhost to the OpenConsole, or the WindowsTerminal - at least so they show up sanely in Task Manager.

Reproduce the issue by setting up defterm, running cmd.exe, and inspecting the resulting process tree in Task Manager. Investigate how cmd.exe and its conhost are handed off to OpenConsole or WindowsTerminal; done means they appear under the appropriate terminal process instead of explorer while preserving the handoff behavior.

Written by the indexing model from the issue text.