`BlockId` removal: `tx-pool` refactor (#1678)

It changes following APIs:
- trait `ChainApi`
-- `validate_transaction`

- trait `TransactionPool` 
--`submit_at`
--`submit_one`
--`submit_and_watch`

and some implementation details, in particular:
- impl `Pool` 
--`submit_at`
--`resubmit_at`
--`submit_one`
--`submit_and_watch`
--`prune_known`
--`prune`
--`prune_tags`
--`resolve_block_number`
--`verify`
--`verify_one`

- revalidation queue

All tests are also adjusted.

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Co-authored-by: command-bot <>
Co-authored-by: Bastian Köcher <git@kchr.de>