* Remove rename for finalized event.

* ADd some docs.

* Document timeout.

* Adds `with_pair!` macro to application-crypto

This macro will "generate" the given code only when the crypto pair is
available. So, when either the `std` or the `full_crypto` feature is
enabled.

* Fix example

* adds finalization support to sc-transaction-pool using MaintainedTransactionPool for finalization events

* adds TransactionStatus::Retracted, notify watchers of retracted blocks, finalized now finalizes, transactions for current finalized -> last finalized block

* adds last_finalized to ChainApi, use generic BlockT for ChainEvent

* fix tests

* Apply suggestions from code review

Co-Authored-By: Tomasz Drwięga <[email protected]>

* tests

* fix tests, docs, lazily dedupe pruned hashes

* fix tests, Cargo.lock

* Apply suggestions from code review

Co-Authored-By: Tomasz Drwięga <[email protected]>

* remove tree_route, last_finalized from ChainApi, add block hash to Finalization and Retracted events

* prune finality watchers

* fix tests

* remove HeaderBackend bound from FullChainApi

* code style nits, terminate stream in finality_timeout

Co-authored-by: Tomasz Drwięga <[email protected]>

* contracts: Allow to distinguish out of gas from other traps

When a contract encounters a runtime error a wasm trap is
triggered and the execution is halted. Currently, no matter
what was the cause for the trap it is always reported as:
DispatchError::Other("contract trapped during execution").

However, the trap that is triggered if a contract exhausts
its gas budget is particulary interesting. Therefore we add
a seperate error message for this cause:
DispatchError::Other("ran out of gas during contract execution").

A test is added hat executes a contract that never terminates.
Therefore it always exhausts is gas budget.

* fixup! contracts: Allow to distinguish out of gas from other traps

Remove overlong lines.

* fixup! contracts: Allow to distinguish out of gas from other traps

Rename Contract to Contracts