feat(flagpole): add support for more detailed owner schema

[cvxluo]

Add the option to define owner via team + email strings, rather than just a string. Supports this change in the options automator: https://github.com/getsentry/sentry-options-automator/pull/5705. This change is temporary until we can move fully to the new schema.

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: All tests successful. No failed tests found.

Additional details and impacted files

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  Lines      402540    400781    -1759     
  Branches    25700     25700              
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- Hits       324549    322730    -1819     
- Misses      77523     77583      +60     
  Partials      468       468