chore: Add prefix to dplyr generated helper files, and skip if env var is set

[krlmlr]

No description provided.

[github-actions]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if 56d2414 is merged into main:

• ✔️001_tpch_01: 21.4ms -> 22.2ms [-0.44%, +8.4%]
• ✔️001_tpch_02: 63.7ms -> 63.7ms [-2.17%, +2.21%]
• ✔️001_tpch_03: 38.4ms -> 38.2ms [-2.14%, +0.87%]
• ✔️001_tpch_04: 22ms -> 22.1ms [-2.15%, +3.02%]
• ✔️001_tpch_05: 56.5ms -> 56.3ms [-1.94%, +0.93%]
• ✔️001_tpch_06: 17.7ms -> 17.5ms [-3.72%, +1.44%]
• ✔️001_tpch_07: 70.5ms -> 70.1ms [-1.57%, +0.65%]
• ✔️001_tpch_08: 91.3ms -> 92ms [-1.86%, +3.43%]
• ✔️001_tpch_09: 74.6ms -> 73.9ms [-2.66%, +0.74%]
• ✔️001_tpch_10: 48.8ms -> 48.8ms [-1.58%, +1.81%]
• ✔️001_tpch_11: 31.8ms -> 31.9ms [-1.46%, +2.16%]
• ✔️001_tpch_12: 21.1ms -> 21.3ms [-1.05%, +3.73%]
• ✔️001_tpch_13: 24.4ms -> 24.4ms [-3.08%, +2.86%]
• ❗🐌001_tpch_14: 22.9ms -> 23.4ms [+0.03%, +3.96%]
• ✔️001_tpch_15: 29.5ms -> 29.4ms [-2.02%, +1.45%]
• ✔️001_tpch_16: 28.8ms -> 29ms [-1%, +2.09%]
• ✔️001_tpch_17: 24.3ms -> 24.6ms [-1.46%, +3.99%]
• ✔️001_tpch_18: 22.2ms -> 22ms [-3.79%, +2.2%]
• ✔️001_tpch_19: 43.9ms -> 44.1ms [-1.46%, +2.12%]
• ✔️001_tpch_20: 43.1ms -> 43.2ms [-1.61%, +2.51%]
• ✔️001_tpch_21: 76.8ms -> 77.7ms [-1.23%, +3.44%]
• ✔️001_tpch_22: 45.1ms -> 44.9ms [-1.99%, +1.21%]
• ✔️010_tpch_01: 78.8ms -> 76.4ms [-10.35%, +4.21%]
• ✔️010_tpch_02: 68.5ms -> 69ms [-1.13%, +2.54%]
• ✔️010_tpch_03: 56.5ms -> 57.8ms [-2.53%, +7.38%]
• ✔️010_tpch_04: 41.7ms -> 41.7ms [-1.79%, +1.82%]
• ✔️010_tpch_05: 86.3ms -> 87.7ms [-0.8%, +4.1%]
• ✔️010_tpch_06: 29.4ms -> 30.8ms [-3.54%, +13.38%]
• ✔️010_tpch_07: 102ms -> 103ms [-1.93%, +3.98%]
• ✔️010_tpch_08: 130ms -> 126ms [-5.94%, +0.72%]
• ✔️010_tpch_09: 115ms -> 119ms [-0.87%, +7.98%]
• ✔️010_tpch_10: 73.9ms -> 72ms [-7.06%, +1.87%]
• 🚀010_tpch_11: 38.7ms -> 37.2ms [-7.34%, -0.05%]
• ✔️010_tpch_12: 50.6ms -> 51.1ms [-2.1%, +3.84%]
• ✔️010_tpch_13: 50.6ms -> 52.1ms [-1.93%, +7.74%]
• ✔️010_tpch_14: 34.1ms -> 34.3ms [-2.89%, +4.34%]
• ✔️010_tpch_15: 51ms -> 48.4ms [-11.96%, +1.53%]
• ✔️010_tpch_16: 39ms -> 39ms [-2.52%, +2.39%]
• ✔️010_tpch_17: 52.3ms -> 53.4ms [-4.39%, +8.43%]
• ✔️010_tpch_18: 52.9ms -> 54ms [-5.7%, +9.91%]
• ✔️010_tpch_19: 83.7ms -> 83.9ms [-1.29%, +1.9%]
• ✔️010_tpch_20: 64.4ms -> 64.1ms [-5.11%, +4.19%]
• ✔️010_tpch_21: 238ms -> 236ms [-3.92%, +2.28%]
• ✔️010_tpch_22: 52.6ms -> 53ms [-1.75%, +3.25%]
• ✔️100_tpch_01: 323ms -> 311ms [-18.47%, +11.04%]
• ✔️100_tpch_02: 124ms -> 123ms [-7.1%, +6.01%]
• ✔️100_tpch_03: 173ms -> 173ms [-4.63%, +5.63%]
• ✔️100_tpch_04: 157ms -> 154ms [-9.62%, +5.9%]
• ✔️100_tpch_05: 270ms -> 252ms [-21.05%, +7.94%]
• ✔️100_tpch_06: 93.5ms -> 95.6ms [-23.71%, +28.05%]
• ✔️100_tpch_07: 228ms -> 217ms [-15.42%, +5.55%]
• ✔️100_tpch_08: 259ms -> 255ms [-15.42%, +12.29%]
• ✔️100_tpch_09: 323ms -> 321ms [-10.31%, +9.42%]
• ✔️100_tpch_10: 217ms -> 213ms [-11.91%, +7.71%]
• ✔️100_tpch_11: 86.8ms -> 84.5ms [-9.74%, +4.39%]
• ✔️100_tpch_12: 174ms -> 184ms [-6.21%, +18.23%]
• ✔️100_tpch_13: 334ms -> 322ms [-13.94%, +6.73%]
• ✔️100_tpch_14: 117ms -> 114ms [-20.85%, +14.93%]
• ✔️100_tpch_15: 197ms -> 200ms [-6.16%, +9.4%]
• ✔️100_tpch_16: 133ms -> 118ms [-30.93%, +8.63%]
• ✔️100_tpch_17: 174ms -> 176ms [-16.33%, +18.39%]
• ✔️100_tpch_18: 200ms -> 197ms [-11.49%, +8.87%]
• ✔️100_tpch_19: 265ms -> 260ms [-17.02%, +13.44%]
• ✔️100_tpch_20: 173ms -> 166ms [-15%, +7.52%]
• ✔️100_tpch_21: 1.27s -> 1.29s [-2.61%, +6.97%]
• ✔️100_tpch_22: 154ms -> 151ms [-11.98%, +7.91%]

Further explanation regarding interpretation and methodology can be found in the documentation.