Motivation and Context

Resolves #10642 -- failure of KernelProcessEventVisibility.Public events to propagate.

Description

First, KernelProcessEvent was configured to use enum values -- though throughout the code, KernelProcessEvent.visibility is compared as an enum.

Second, when handling events emitted by a KernelProcessStep, any Public visibility events are/were passed through LocalStep.scoped_event (which modifies the event's namespace) before queueing up any matching edges on the source step. This change to the event namespace effectively prevents the event from propagating (since I don't know how we'd 'listen' for events on the local process handle from within the function that builds that very process...)

Allowing visibility on KernelProcessEvent to be an enum, combined with an exchange in the order of processing event messages (matching event to edge before re-emitting any events marked as 'Public') causes public events to propagate as expected.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄