* [server] move FGA calls into AuthProviderService
* split internal upsert method `updateAuthProvider` into create and update
* refactor: move `getAuthProviders` logic from gitpod-server-impl to auth-provider-service
* adding db tests for auth provider server
* use redacted results in service
* Fix typos
* extract helper functions for scopes
* add more tests
* as regular member, should find org-level providers if no built-in providers present
* as regular member, should find only built-in providers if present
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Co-authored-by: Huiwen <mhqnwt@gmail.com>