Refactored logic for what selection type is allowed in a SGraphActionMenu to the widgets that react to the selection.
#jira UE-11644 - Selected BP Variables do not refresh details properly
[CL 2493909 by Michael Schoell in Main branch]
UETOOL-213 - Minimize Slate FString -> FText conversion (remove SLATE_TEXT_ATTRIBUTE)
This fixes any editor/engine specific code that was passing text to Slate as FString rather than FText.
[CL 2399803 by Jamie Dale in Main branch]
#add Added UEdGraphNode::GetNodeNativeTitle to return a native title for a node.
#add Added UEdGraphNode::GetNodeSearchTitle to return the native and localized title for a node, together, for searching.
#add Can hold "alt" over a node (in the graph panel, or the palette) to see the native name of the node.
#ttp 331252 - Blueprints: Editor: L10N: Blueprints need to consistently show localized node names and when searching need to search both the localized name and the native name
#codereview justin.sargent
[CL 2044506 by Michael Schoell in Main branch]
