+ Added StateTree parameters usable for data bindings and that could be overriden on context initialization by a StateTreeReference
+ Added StateTreeReference struct to hold a reference to a StateTree asset along with a list of values to parameterized the tree.
+ Added named external data items that are defined bt the Schema and for which values must be provided at runtime through the execution context.
+ Added delegate OnPostCompile after successful compilation. The StateTreeReference listens to it to validate its parameters
+ EditorData now contains its own version of the schema and parameters. On successful compilation they are copied over the StateTree own properties.
#rnx
#rb mikko.mononen
#preflight 6255d281647ad886b3593cb0
[CL 19727363 by Yoan StAmant in ue5-main branch]
