SYSML2_ — State machine graphical notation for entry/exit/do actions inconsistent

Current GBNF uses the textual notation to represent state entry/do/exit actions within a "state actions" compartment.
This does not allow to describe state actions in a graphical way and also requires the graphical modeler to use more extended textual syntax.

State machine graphical notation for entry/exit/do actions inconsistent

Need to align state graphical notation with structured actions by using dedicated compartments to represent nested actions. This implies dedicated entry, exit, and do action compartments on state nodes.