VariantManager: Move files to VariantManagerContentEditor
VariantManager: Separate EPropertyValueCategory enum to decouple DatasmithImporter and VariantManager
VariantManager: UI and minor tweaks
- Better way of detecting when we should use the component name or property name for root components;
- Fix lighter gray stripe below actor nodes in 4.24;
- Change auto-expose icon to a standard 'record' icon;
VariantManager: Fix build error for Mac
#jira UE-81398
#jira UE-81500
#jira UE-81038
#jira UE-81571
#rb Daniel.Coelho
[CL 9654886 by JeanMichel Dignard in 4.24 branch]