Add support for handling blockchain reverts

[re-gius]

Description

This PR builds on top of the work of #10453 (thanks @AlexandruCihodaru ) and adds support for handling blockchain reverts, useful in testing environments with RPCs like evm_revert or anvil_reset.

Changes

• Add ChainEvent::Reverted variant to represent backward blockchain progression
• Add EnactmentAction::HandleReversion to route revert events appropriately
• Implement handle_reverted() method that:
  • identifies and removes all views beyond the revert point (both active and inactive)
  • collects transactions from retracted blocks via included_transactions cache or API
  • removes those transactions from mempool (they can be resubmitted later)
  • creates a fresh view at the new head populated from the current mempool state
  • atomically updates most_recent_view and cleans up listener references

Review Notes

• We always create a fresh view at the revert target block rather than reusing stale views, ensuring the view reflects the current mempool state
• Pending transactions will appear in the new view only if they pass revalidation against the new head's state
• Transactions from reverted blocks are removed without banning, allowing resubmission
• View removal and most_recent_view update are performed atomically by holding all three locks (most_recent_view,
  active_views, inactive_views) simultaneously, following the same pattern as ViewStore::insert_new_view_sync to prevent race conditions, as suggested by @michalkucharczyk

[re-gius]

/cmd prdoc --audience runtime_dev --bump patch

[paritytech-workflow-stopper]

All GitHub workflows were cancelled due to failure one of the required jobs.
Failed workflow url: https://github.com/paritytech/polkadot-sdk/actions/runs/21218327371
Failed job name: fmt

[re-gius]

/cmd fmt