Change: refine the `RaftEntry` trait #4326

Job	Run time
cluster-benchmark (cluster_benchmark)	52s
openraft-test-bench (nightly)	59s
openraft-feature-test (nightly)	54s
openraft-feature-test (nightly, serde)	51s
rt-monoio	48s
stores (stores/memstore)	1m 2s
openraft-feature-test (nightly, serde,singlethreaded)	54s
test-crate-openraft (stable)	54s
test-crate-tests (stable, 0)	3m 45s
test-crate-openraft (nightly)	49s
Build (nightly, bench,serde,bt,singlethreaded)	55s
test-crate-tests (nightly, 30)	3m 16s
test-crate-tests (nightly, 0, single-term-leader)	2m 58s
tests-feature-test (nightly)	3m 5s
tests-feature-test (nightly, single-term-leader)	3m 5s
examples (stable, memstore)	48s
lint	4m 13s
examples (stable, rocksstore)	6m 3s
examples (stable, raft-kv-memstore)	2m 35s
examples (stable, raft-kv-memstore-grpc)	2m 5s
examples (stable, raft-kv-memstore-network-v2)	54s
examples (stable, raft-kv-memstore-opendal-snapshot-data)	1m 59s
examples (stable, raft-kv-memstore-singlethreaded)	53s
examples (stable, raft-kv-rocksdb)	6m 27s
examples (nightly, memstore)	1m 0s
examples (nightly, rocksstore)	10m 45s
examples (nightly, raft-kv-memstore)	2m 22s
examples (nightly, raft-kv-memstore-grpc)	1m 43s
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 15s
examples (nightly, raft-kv-rocksdb)	11m 24s
	1h 22m 16s

Provide feedback