Sugar: Propagate user-given annotations from original expr into Sugar.Expression
GUI is hard-coded to use ExpressionN with ()
Sugar.MStorePoint
Sugar.Definition[U/N] are parameterized on ()
Sugar.makeTypeInfo: Can do annotations
GUI uses ExprGuiM.Payload and SugarExpr
Use SugarExpr/ExprGuiM.Payload instead of rHiddenGuids
oops: assignCursorPrefix does not strip the suffix

That caused exprs to assign anything starting with their prefix to the prefix
Collapsed expressions steal the payloads of the expanded terms.

The collapsed expression will get marked.