refactor: seat tracker roster and permissions

[cristinabaldor]

Pull Request

Summary & Motivation

add placeholder teammates (Open, New Hire, Scoot Sub) to the roster via union, rework the permission levels.

Self-review

• [ ] Update due date, assignee, and priority on our TEAMster Asana Project

  If this is a same-day request, please flag that in Slack

• [ ] Format has been run on all modified files

• [ ] Ensure you are using the union_dataset_join_clause() macro for queries that employ any models from these datasets:

  • deanslist
  • edplan
  • iready
  • pearson
  • powerschool
  • renlearn
  • titan

Troubleshooting

• SqlFluff Rules Reference
• Trunk
• dbt

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