feat: remove some redundent clone/conversion on constructing MergeScan stream #19408

Job	Run time
Check License Header	2m 22s
Toml Check	25s
Build GreptimeDB binary (profile-CI) (ubuntu-20.04)	2m 52s
Check typos and docs	7s
Check (windows-2022)	18m 9s
Check (ubuntu-20.04)	2m 17s
Clippy	3m 25s
Build GreptimeDB binaries (ubuntu-20.04)	2m 41s
Rustfmt	31s
coverage	17m 57s
Sqlness Test (Basic)	2m 32s
Fuzz Test (fuzz_create_table)	5m 57s
Sqlness Test (Remote WAL)	2m 44s
Fuzz Test (fuzz_alter_table)	6m 8s
Fuzz Test (fuzz_create_database)	6m 12s
Fuzz Test (fuzz_create_logical_table)	6m 10s
Fuzz Test (fuzz_alter_logical_table)	6m 21s
Fuzz Test (fuzz_insert)	7m 48s
Fuzz Test (fuzz_insert_logical_table)	8m 11s
Unstable Fuzz Test (unstable_fuzz_create_table_standalone)	5m 0s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_migrate_mito_regions)	7m 0s
Fuzz Test (Distributed, Remote WAL, fuzz_create_table)	9m 46s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_failover_mito_regions)	10m 5s
Fuzz Test (Distributed, Remote WAL, fuzz_alter_table)	10m 5s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_failover_metric_regions)	9m 1s
Fuzz Test (Distributed, Remote WAL, fuzz_create_database)	8m 30s
Fuzz Test (Distributed, Remote WAL, fuzz_create_logical_table)	9m 9s
Fuzz Test (Distributed, Remote WAL, fuzz_alter_logical_table)	10m 47s
Fuzz Test (Distributed, Remote WAL, fuzz_insert)	9m 39s
Fuzz Test (Distributed, Remote WAL, fuzz_insert_logical_table)	9m 9s
	3h 21m 0s

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