message: Fix settings not updating on reload
  In we started passing a child of the `TerminalSettings` to the
  control upon tab initialization, but forgot to do the same when new
  controls get created on a pane split.
  ## Validation Steps Performed
  Settings reload with multiple panes works
  Closes
diff: @@ -882,7 +882,7 @@ namespace winrt::TerminalApp::implementation
  if (debugConnection) // this will only be set if global debugging is on and tap is active
  {
  - TermControl newControl{ settings, debugConnection };
  + TermControl newControl{ *(winrt::get_self<TerminalSettings>(settings)->CreateChild()), debugConnection };
  _RegisterTerminalEvents(newControl, *newTabImpl);
  // Split (auto) with the debug tap.
  newTabImpl->SplitPane(SplitState::Automatic, 0.5f, profileGuid, newControl);
  @@ -1865,7 +1865,7 @@ namespace winrt::TerminalApp::implementation
  return;
  }
  - TermControl newControl{ controlSettings, controlConnection };
  + TermControl newControl{ *(winrt::get_self<TerminalSettings>(controlSettings)->CreateChild()), controlConnection };
  // Hookup our event handlers to the new terminal
  _RegisterTerminalEvents(newControl, *focusedTab);
  