Refactor: `ReplicationCore` get a snapshot directly from state machine, via `SnapshotReader` #3377

Job	Run time
cluster-benchmark (cluster_benchmark)	46s
examples (stable, memstore)	41s
examples (stable, raft-kv-memstore)	2m 22s
lint	6m 52s
examples (stable, raft-kv-memstore-generic-snapshot-data)	1m 2s
examples (stable, raft-kv-memstore-opendal-snapshot-data)	1m 34s
examples (stable, raft-kv-memstore-singlethreaded)	1m 5s
openraft-feature-test (nightly)	51s
openraft-test (stable, 0)	3m 15s
examples (stable, raft-kv-rocksdb)	7m 1s
openraft-feature-test (nightly, serde)	54s
openraft-test (nightly, 30)	3m 40s
examples (nightly, memstore)	57s
openraft-feature-test (nightly, single-term-leader)	55s
openraft-test (nightly, 0, single-term-leader)	3m 29s
examples (nightly, raft-kv-memstore)	2m 14s
openraft-feature-test (nightly, single-term-leader,serde,singlethreaded)	53s
examples (nightly, raft-kv-memstore-generic-snapshot-data)	1m 20s
examples (nightly, raft-kv-memstore-opendal-snapshot-data)	1m 57s
openraft-test-bench (nightly)	56s
stores (stores/memstore)	53s
examples (nightly, raft-kv-memstore-singlethreaded)	1m 23s
Build (nightly, bench,serde,bt,singlethreaded)	51s
stores (stores/rocksstore)	6m 18s
examples (nightly, raft-kv-rocksdb)	12m 51s
tests-feature-test (nightly)	3m 16s
stores (stores/sledstore)	1m 5s
tests-feature-test (nightly, single-term-leader)	3m 9s
tests-feature-test (nightly, loosen-follower-log-revert)	3m 14s
	1h 15m 44s

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