Updated the organization membership model to operate at the tenant level, aligning with Plan 3. This change introduces new interfaces and modifies existing ones to accommodate tenant-centric operations, including the `InviteMemberRequest` and `TenantInviteCandidate`. The search functionality for inviting members has been updated to reflect this shift, allowing for tenant-based searches instead of user-based. Additionally, internationalization files have been updated to ensure consistent messaging across languages regarding tenant membership and roles.
Refs: #1303