Token simulation allows incoming sequence flows for events after an event based gateway

[marstamm]

Describe the Bug

Reported as https://github.com/camunda/camunda-modeler/issues/3984

When adding token simulation to the modeler, I can model non spec-compliant diagrams, which are not possible without the plugin.

Steps to Reproduce

Try to model the above diagram

Expected Behavior

Environment

• Host (Browser/Node version), if applicable: [e.g. MS Edge 18, Chrome 69, Node 10 LTS]
• OS: [e.g. Windows 7]
• Library version: [e.g. 2.0.0]