Refactor organization and user management components/tests for simplification and improved clarity

- Removed unused properties (`slug`, `is_active`, etc.) in organization and user-related components and test data.
- Simplified function data typing by removing redundant `any` usage.
- Updated `params` in `OrganizationMembersPage` for Promise resolution and async handling.
- Cleaned up unused variables and streamlined form handling in `AddMemberDialog`.

frontend/tests/components/admin/organizations/OrganizationActionMenu.test.tsx

@@ -32,7 +32,6 @@ describe('OrganizationActionMenu', () => {
   const mockOrganization: Organization = {
     id: '1',
     name: 'Acme Corporation',
-    slug: 'acme-corporation',
     description: 'Leading provider',
     is_active: true,
     created_at: '2025-01-01T00:00:00Z',