<!-- This template is a great use for issues that are feature::additions or technical tasks for larger issues.--> ### Proposal In order to extend SCIM support for self managed users, we need to add SCIM API such that it can support individual instance level resources. This task contains the high level scope for that effort. @bdenkovych has proposed starting with the following changes in https://gitlab.com/gitlab-org/gitlab/-/issues/12823#note_1083854586. * Refactor `ScimIdentity` to allow identity creation without a group. Treat such identities to be related to instance level. * Extend `ScimFinder`. Add possibility to search for instance level-related identities(those ones that are not scoped to a group) * Extend `::EE::Gitlab::Scim::ProvisioningService.new(group, params)`. Make `group` argument to be optional. Apply provisioning steps for instance level if there is no group. * Extend `::EE::Gitlab::Scim::ReprovisionService.new(identity)`. If passed scim identity is not tied to a group then apply steps for instance level - unblock user. * Extend `::EE::Gitlab::Scim::DeprovisionService.new(identity)`. If passed scim identity is not tied to a group then apply steps for instance level - block user. * Add the endpoints <!-- Consider adding related issues and epics to this issue. You can also reference the Feature Proposal Template (https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitlab/issue_templates/Feature%20proposal%20-%20detailed.md) for additional details to consider adding to this issue. Additionally, as a data oriented organization, when your feature exits planning breakdown, consider adding the `What does success look like, and how can we measure that?` section. --> <!-- Label reminders Use the following resources to find the appropriate labels: - https://gitlab.com/gitlab-org/gitlab/-/labels - https://about.gitlab.com/handbook/product/categories/features/ -->