Reuse hashes buffer when emitting partial join results

[alamb]

Proposed addition to apache#8020 to reuse a buffer to output hashing

I ran benchmarks and it seems to have helped slightly compared to apache#8020 (review) maybe

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Benchmark tpch_mem.json
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┏━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━┓
┃ Query        ┃ main_base ┃ alamb_hash_reuse ┃       Change ┃
┡━━━━━━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━┩
│ QQuery 1     │  216.45ms │         212.86ms │    no change │
│ QQuery 2     │   47.26ms │          48.76ms │    no change │
│ QQuery 3     │   84.77ms │          81.57ms │    no change │
│ QQuery 4     │   76.74ms │          76.78ms │    no change │
│ QQuery 5     │  126.54ms │         132.21ms │    no change │
│ QQuery 6     │   17.54ms │          17.39ms │    no change │
│ QQuery 7     │  314.92ms │         333.80ms │ 1.06x slower │
│ QQuery 8     │   85.91ms │          88.57ms │    no change │
│ QQuery 9     │  130.72ms │         134.49ms │    no change │
│ QQuery 10    │  163.45ms │         156.90ms │    no change │
│ QQuery 11    │   36.92ms │          35.54ms │    no change │
│ QQuery 12    │   70.09ms │          71.33ms │    no change │
│ QQuery 13    │   83.92ms │          89.31ms │ 1.06x slower │
│ QQuery 14    │   27.94ms │          27.52ms │    no change │
│ QQuery 15    │   67.40ms │          65.91ms │    no change │
│ QQuery 16    │   47.03ms │          47.74ms │    no change │
│ QQuery 17    │  168.58ms │         174.17ms │    no change │
│ QQuery 18    │  444.32ms │         479.44ms │ 1.08x slower │
│ QQuery 19    │   67.85ms │          65.16ms │    no change │
│ QQuery 20    │  119.52ms │         125.33ms │    no change │
│ QQuery 21    │  359.70ms │         378.62ms │ 1.05x slower │
│ QQuery 22    │   31.49ms │          30.35ms │    no change │
└──────────────┴───────────┴──────────────────┴──────────────┘