[GTRIA-1260] - Adds attendee meta data to Tickets Commerce Completed Order emails

[masoodahmed]

🎫 Ticket

GTRIA-1260

🗒️ Description

🎥 Artifacts

Before: https://imgur.com/CjpVyqd After: https://imgur.com/ea6PhRv

✔️ Checklist

• [x] Changelog entry in the readme.txt file.
• [ ] Code is covered by NEW wpunit or integration tests.
• [ ] Code is covered by EXISTING wpunit or integration tests.
• [ ] Are all the required tests passing?
• [ ] Automated code review comments are addressed.
• [x] Have you added Artifacts?
• [x] Check the base branch for your PR.
• [ ] Add your PR to the project board for the release.