serviceability: restrict delete instructions to valid statuses

[martinsander00]

Resolves: #2223

Summary

• Delete instructions for all serviceability entities (Location, Exchange, Contributor, Device, Link, User, MulticastGroup) now verify the account is in an appropriate status before allowing deletion
• Entities with a Suspended status (Location, Exchange, Contributor, MulticastGroup) allow deletion from both Activated and Suspended
• Device allows all operational statuses: Activated, DeviceProvisioning, LinkProvisioning, and Drained. Like links, devices go through provisioning phases after activation (DeviceProvisioning → LinkProvisioning → Activated) and can be drained for maintenance. Restricting to only Activated would leave devices stuck in provisioning or drained states with no way to clean them up.
• Link allows all active statuses: Activated, Provisioning, SoftDrained, and HardDrained. Links go through a Provisioning phase after activation (before the link health oracle transitions them to Activated), and can also be drained for maintenance.
• User allows Activated, SuspendedDeprecated, and Banned to support the ban-then-delete workflow used in the E2E user ban test

Testing Verification

• New integration tests added and passing for delete-from-Suspended:
  • test_contributor_delete_from_suspended
  • test_exchange_delete_from_suspended
  • test_location_delete_from_suspended
• New integration tests for link delete status restrictions:
  • test_link_delete_fails_from_pending — verifies deletion from Pending returns InvalidStatus
  • test_link_delete_from_soft_drained — verifies deletion from SoftDrained succeeds
  • test_link_delete_from_hard_drained — verifies deletion from HardDrained succeeds
• New integration tests for device delete status restrictions:
  • test_device_delete_fails_from_pending — verifies deletion from Pending returns InvalidStatus
  • test_device_delete_from_drained — verifies deletion from Drained succeeds
• Device and link provisioning cases are covered by the E2E backward compatibility test (entities stay in provisioning states in that environment)
• Full test suites for contributor, exchange, location, link, and device pass with no regressions