Change: refine the `RaftEntry` trait #4330

Job	Run time
lint	3m 53s
cluster-benchmark (cluster_benchmark)	48s
examples (stable, memstore)	1m 6s
examples (stable, rocksstore)	5m 46s
openraft-feature-test (nightly)	50s
examples (stable, raft-kv-memstore)	2m 51s
openraft-test-bench (nightly)	1m 1s
openraft-feature-test (nightly, serde)	51s
examples (stable, raft-kv-memstore-grpc)	1m 54s
openraft-feature-test (nightly, serde,singlethreaded)	53s
examples (stable, raft-kv-memstore-network-v2)	53s
rt-monoio	41s
examples (stable, raft-kv-memstore-opendal-snapshot-data)	1m 22s
stores (stores/memstore)	55s
examples (stable, raft-kv-memstore-singlethreaded)	1m 0s
test-crate-openraft (stable)	47s
examples (stable, raft-kv-rocksdb)	7m 22s
test-crate-tests (stable, 0)	3m 5s
test-crate-openraft (nightly)	51s
examples (nightly, memstore)	57s
test-crate-tests (nightly, 30)	3m 13s
test-crate-tests (nightly, 0, single-term-leader)	3m 9s
Build (nightly, bench,serde,bt,singlethreaded)	51s
examples (nightly, rocksstore)	10m 20s
tests-feature-test (nightly)	2m 58s
examples (nightly, raft-kv-memstore)	2m 32s
tests-feature-test (nightly, single-term-leader)	2m 59s
examples (nightly, raft-kv-memstore-grpc)	1m 45s
examples (nightly, raft-kv-memstore-network-v2)	1m 16s
examples (nightly, raft-kv-memstore-opendal-snapshot-data)	1m 27s
examples (nightly, raft-kv-memstore-singlethreaded)	1m 18s
examples (nightly, raft-kv-rocksdb)	11m 29s
	1h 21m 3s

Provide feedback