Notes on waypoints aren't saved with the plan

🚧 THIS IS A TICKET MIGRATED FROM UPVOTY. The original ticket and comments will be available for a limited time over at:
https://abrp.upvoty.com/b/report-a-bug/notes-on-waypoints-arent-saved-with-the-plan/
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Repro steps:

1. Create a plan with some waypoints
2. Add some notes to the waypoints
3. Save the Plan
4. Load the plan
   Notice that the notes don't exist anymore