Problem serialization of event data PortSpecification instances

[philip-alldredge]

While adding prototype support to the graphical editor, I've come across a serialization issue.

Steps to Reproduce

1. Programatically create a FeaturePrototypeBinding and a PortSpecification with and event data category.
2. Serialize back to AADL.
3. The keyword used for event data is incorrect. eventData is serialized instead of event data.

package prototype_test
public
	with interfaces;
	with Base_Types;

	system subsystem
		prototypes
			iface_pt: feature group;
	end subsystem;

	system test_system
	end test_system;

	system implementation test_system.impl
		subcomponents
			ss: system subsystem (iface_pt => feature group interfaces::subsystem_interface (
					message_cpt => data Base_Types::String, event_fpt => out eventData port Base_Types::Integer));
	end test_system.impl;
end prototype_test;

[philip-alldredge]

@lwrage this is blocking the current Graphical Editor prototype work(#2277) but I'm not knowledgeable enough in this area to suggest a fix. It appears to be caused by the xtext grammar or formatter. PortSpecification is the only part of the grammar to reference PortCategory. The prototype support branch is complete enough to easily test out fixes to this issue.

[lwrage]

@philip-alldredge Could you check if the change on branch 2300_serialize_event_data fixes the issue?

[philip-alldredge]

@lwrage yes, the change in that branch fixes the problem.