Support Group Sync w/ SCIM

Part of : https://github.com/coder/coder/issues/15830

**Quote:**integrating Coder into our in house identity system and i noticed that Coder does not support group sync via SCIM as mentioned in this [issue](https://github.com/coder/coder/issues/15830).

**Impact:**high. we will not be able to automatically onboard users given their granted permission controlled through google groups
# of users who would be impacted: all new users
if this would be a blocker or nice to have: soft blocker, this will slow down our adoption if we need to manually check their group status and periodically sync their permissions

**Manual Next Steps:** Ask to move to another step? Manual pre provision accounts- assignment once user is logged in. Platform team manages.

まずリンク先の issue #15830 を読んで、要求されている SCIM グループ同期の範囲を理解してください。Done は、手動チェックや定期的な更新に頼るのではなく、ユーザーの自動オンボーディングと、アイデンティティシステムのグループからの権限同期をサポートすべきです。

索引モデルが issue の本文から書いたものです。