Refactor: delete async-trait, fix typo, use tokio to replace async_std #29

Job	Run time
openraft-test-bench (nightly)	54s
cluster-benchmark (cluster_benchmark)	44s
external-stores (stores/rocksstore-v2)	6m 0s
openraft-feature-test (nightly)	49s
openraft-feature-test (nightly, serde)	48s
openraft-test (stable, 0)	2m 58s
openraft-feature-test (nightly, single-term-leader)	50s
openraft-test (nightly, 30)	3m 14s
stores (memstore)	41s
openraft-feature-test (nightly, single-term-leader,serde,singlethreaded)	49s
stores (rocksstore)	6m 13s
openraft-test (nightly, 0, single-term-leader)	2m 59s
stores (rocksstore-compat07)	5m 53s
Build (nightly, bench,serde,bt,singlethreaded)	49s
stores (sledstore)	53s
examples (stable, raft-kv-memstore)	2m 14s
lint	6m 22s
examples (stable, raft-kv-memstore-singlethreaded)	1m 15s
examples (stable, raft-kv-rocksdb)	7m 51s
examples (nightly, raft-kv-memstore)	2m 10s
tests-feature-test (nightly)	2m 47s
examples (nightly, raft-kv-memstore-singlethreaded)	1m 13s
tests-feature-test (nightly, single-term-leader)	2m 48s
examples (nightly, raft-kv-rocksdb)	12m 4s
tests-feature-test (nightly, loosen-follower-log-revert)	2m 49s
	1h 16m 7s

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