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.

Read the linked issue #15830 first to understand the requested SCIM group-sync scope. Done should support automatically onboarding users and syncing permissions from their identity-system groups instead of relying on manual checks and periodic updates.

Vom Indexierungsmodell aus dem Issue-Text verfasst.