UE-14641 - Fix PushMenu() to use QueryPopupMethod()
Pretty big refactor
Adds IMenu as way to identify menus. Replaces referring to menus as SWindows.
Lots of uses of PushMenu() fixed up to match new API
#codereview Nick.Atamas
[CL 2579277 by Chris Wood in Main branch]
Newly installed versions of the engine will now attempt to copy the project-agnostic config settings from a previous engine installation. This happens by way of a versioned manifest that copies old versions when the manifest does not exist, or is a different version. This code path is benign for non-installed versions of the engine (or FPaths::ShouldSaveToUserDir() is false).
EditorGameAgnosticSettings and EditorUserSettings ini paths have been renamed to EditorSettings and EditorPerProjectUserSettings respectively to better convey their purpose. In general, most settings should be saved in EditorSettings (project-agnostic) so that they apply regardless of which project is open. We have some way to go migrating existing settings for this to be the case, however.
Some previously per-project configuration files are now project-agnostic (such as Editor.ini, EditorKeyBindings.ini, and EditorLayout.ini)
GEditor->Access...Settings and GEditor->Get...Settings have been removed in favor of direct access of the CDO through GetMutableDefault<> and GetDefault<> respectively. Global config ini filenames that are not set up are now neither loaded nor saved on build machines, to handle the problem of indeterminate state more generically.
This addresses UETOOL-270 (Most editor preferences should be project-agnostic)
[CL 2517558 by Andrew Rodham in Main branch]
Some P4V problem with backing out large changelist missed some files.
#codereview Robert.Manuszewski
[CL 2481366 by Jaroslaw Palczynski in Main branch]
