[v5] Fix crash with direct influence but nil direct id

[nan-li]

Description

One Line Summary

Cherry-pick of https://github.com/OneSignal/OneSignal-iOS-SDK/pull/1311 from main.

Details

Motivation

Fixes a crash when a session has a direct influence but the direct id is nil.

This does not resolve getting into this situation in the first place since we should not have a direction session without a direct id, but this will at least prevent a crash when the issue happens. Instead we will log an error.

Testing

Unit testing

Unit test was also cherry-picked even though it will not run.

Manual testing

None on this PR

Affected code checklist

• [ ] Notifications
  • [ ] Display
  • [ ] Open
  • [ ] Push Processing
  • [ ] Confirm Deliveries
• [x] Outcomes
• [x] Sessions
• [ ] In-App Messaging
• [ ] REST API requests
• [ ] Public API changes

Checklist

Overview

• [x] I have filled out all REQUIRED sections above
• [x] PR does one thing
• [x] Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• [x] I have included test coverage for these changes, or explained why they are not needed
• [x] All automated tests pass, or I explained why that is not possible
• [x]I have personally tested this on my device, or explained why that is not possible

Final pass

• [x] Code is as readable as possible.
• [x] I have reviewed this PR myself, ensuring it meets each checklist item

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This change is 

[nan-li]

I think this was a change that we might've ended up reverting because it caused other issues. Could you check the current state of main? Is this change there or was it reverted?

Main contains these same changes. It was this PR https://github.com/OneSignal/OneSignal-iOS-SDK/pull/1240 that was reverted in https://github.com/OneSignal/OneSignal-iOS-SDK/pull/1251.