Revert "block: row: Idling mechanism re-factoring"

This reverts commit 38f99ccb7a7c7fb21b9189e6f494ee50e249c8a0.
Revert "block: row: Dispatch requests according to their io-priority"

This reverts commit 0bf380683353cc757db41fc2bf5f75277baa45ec.
Revert "row: Add support for urgent request handling"

This reverts commit 5c5d22b70c22fd4210fe0cc95a2011a034678fd9.
Revert "row: Adding support for reinsert already dispatched req"

This reverts commit 06b31a75a7a45c4fd29fa67a323cd15cb085a987.