feat(zero_trust_organization): support v4 to v5 migration

[ssicard]

Supports v4 to v5 migration for zero_trust_organization resource.

Import-only Resource Pattern

NOTE: This is an import-only resource. It does not get created by terraform, but instead only gets edited by terraform. The e2e tests make the assumption that zero trust is already set up through dash for testing accounts. The following changes were made to support this pattern:

• adding an import annotation ( tf-migrate:import-address=${var.cloudflare_account_id})
• supporting import in the end to end test runner

Changes

• handles resource renames from v4 names: zero_trust_access_organization, access_organization
• block to attribute support
• adds defaults added in v5 to state

End To End Tests

========================================
✓ E2E Test Complete!
========================================

Summary:

  Step 1: v4 terraform apply
    Status: ✓ SUCCESS

  Step 2: Migration (v4 → v5)
    Status: ✓ SUCCESS

  Step 3: v5 plan (before apply)
    Status: ✓ No changes needed

  Step 4: v5 terraform apply
    Status: ✓ SUCCESS

  Step 5: v5 plan (after apply)
    Status: ✓ SUCCESS - Stable state achieved
    Result: No changes detected