Avoid eth_blockNumber returning 0x00 when mapping-sync lags (polkadot-evm#1832)

* Add latest_block_hash_scans_past_stale_reorg_window test

* Add rare-path exhaustive fallback

* Use persisted_number-1 as start when it is stale

* Coderabbit review

* Throtled exhaustive fallback log and scan

* lint + scan_limit == 0

* editorconfig + better starting point to continue scanning

* Bounded scan before persisted-pointer

* 4 layers before genesis fallback + better tests

* Add Layer 4: deep recovery

* Deep recovery before persisted pointer

* Remove redundant tokio from dev deps

Author: arturgontijo