Allow Beyond Identity Integration to be inheritable

What does this MR do and why?

Allow custom settings to propagate through groups without preserving custom settings for descendant integrations

These custom settings will be created/destroyed in following MRs:

• Create default instance specific integrations
• Update integration exclusions services to handle groups
• Update exclusions graphql endpoints to handle groups

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Query plans

From https://gitlab.com/gitlab-org/gitlab/-/blob/f79ea84570d3fef1a839361bad9f2b7db39e53e5/app/services/integrations/propagate_service.rb#L48

• https://console.postgres.ai/gitlab/gitlab-production-main/sessions/28494/commands/88970

Related to #454372 (closed)