Right now, we store GUIDs in panes and most of the functions for interacting
with profiles on the settings model take GUIDs and look up profiles.
This pull request changes how we store and look up profiles to prefer profile
objects. Panes store strong references to their originating profiles, which
simplifies settings lookup for CloseOnExit and the bell settings. In fact,
deleting a pane's profile no longer causes it to forget which CloseOnExit
setting applies to it. Duplicating a pane that is hosting a deleted profile
(#5047) now duplicates the profile, even though it is otherwise unreachable.
This makes the world more consistent and allows us to _eventually_ support panes
hosting profiles that do not have GUIDs that can be looked up in the profile
list. This is a gateway to #6776 and #10669, and consolidating the profile
lookup logic will help with #10952.
PR #10588 introduced TerminalSettings::CreateWithProfile and made
...CreateWithProfileByID a thin wrapper over top it, which looked up the profile
by GUID before proceeding. It has also been removed, as its last caller is gone.
Closes#5047
f6f5598c9c