feat: add optional bench_scope feature for stable-structures

[maksymar]

This PR introduces an optional bench_scope feature for stable-structures.

When enabled, it adds canbench_rs scopes to selected functions.
The feature is disabled by default to avoid overhead during benchmarking.
This allows benchmarking with or without internal measurement code.

CSV report in google sheets

[github-actions]

canbench 🏋 (dir: .) 6dbf8cf 2025-05-20 13:20:21 UTC

✅ ./canbench_results.yml is up to date
📦 canbench_results_benchmark.csv available in artifacts

---------------------------------------------------

Summary:
  instructions:
    status:   Improvements detected! 🟢
    counts:   [total 304 | new 0 | improved 262 | regressed 0 | unchanged 42]
    change:   [min -303.39M | med -79.44M | max +914]
    change %: [min -21.06% | med -11.18% | max 0.00%]

  heap_increase:
    status:   Improvements detected! 🟢
    counts:   [total 304 | new 0 | improved 68 | regressed 0 | unchanged 236]
    change:   [min -53 | med 0 | max 0]
    change %: [min -100.00% | med 0.00% | max 0.00%]

  stable_memory_increase:
    status:   No significant changes detected 👍
    counts:   [total 304 | new 0 | improved 0 | regressed 0 | unchanged 304]
    change:   [min 0 | med 0 | max 0]
    change %: [min 0.00% | med 0.00% | max 0.00%]

---------------------------------------------------

Only significant changes:
| status | name                                         |     ins |  ins Δ% | HI |    HI Δ% | SMI |  SMI Δ% |
|--------|----------------------------------------------|---------|---------|----|----------|-----|---------|
|   -    | btreemap_v2_remove_vec_1024_128              |   5.02B |  -2.01% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_contains_blob_512_128            |   2.62B |  -2.10% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_blob_512_128                 |   2.66B |  -2.24% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_vec_1024_128                 |   2.92B |  -2.41% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_insert_blob_1024_128             |   5.10B |  -2.48% |  0 | -100.00% | 196 |   0.00% |
|   -    | btreemap_v2_mem_manager_get_blob512_u64      |   2.76B |  -2.79% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_last_blob_512_128            |   5.05B |  -2.82% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_first_blob_512_128           |   5.17B |  -2.97% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_vec_512_128                  |   1.83B |  -3.02% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_contains_vec_512_128             |   1.81B |  -3.04% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_mem_manager_insert_blob512_u64   |   2.96B |  -3.08% |  0 | -100.00% |   0 |   0.00% |
|   -    | btreemap_v2_mem_manager_remove_blob512_u64   |   3.85B |  -3.15% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_mem_manager_contains_blob512_u64 |   2.72B |  -3.21% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_contains_vec_1024_128            |   2.88B |  -3.21% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_contains_blob_256_128            |   1.48B |  -3.34% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_remove_vec_512_128               |   3.27B |  -3.37% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_blob_256_128                 |   1.51B |  -3.57% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_remove_blob_512_128              |   3.60B |  -3.61% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_insert_vec_1024_128              |   3.32B |  -3.94% |  0 |    0.00% | 193 |   0.00% |
|   -    | btreemap_v2_insert_blob_512_128              |   2.86B |  -3.94% |  0 | -100.00% | 111 |   0.00% |
|   -    | btreemap_v2_remove_vec_256_128               |   2.31B |  -4.06% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_first_blob_256_128           |   3.09B |  -4.15% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_first_vec_1024_128           |   5.76B |  -4.18% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_vec_256_128                  |   1.23B |  -4.30% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_last_blob_256_128            |   3.02B |  -4.32% |  0 |    0.00% |   0 |   0.00% |
|  ...   | ... 212 rows omitted ...                     |         |         |    |          |     |         |
|   -    | btreemap_v2_insert_u64_u64                   | 431.51M | -15.80% |  0 | -100.00% |   6 |   0.00% |
|   -    | btreemap_v2_pop_last_blob_32_4               | 787.77M | -15.88% |  0 | -100.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_blob_32_256                  | 351.58M | -15.90% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_insert_u64_vec8                  | 429.93M | -16.02% |  0 | -100.00% |  21 |   0.00% |
|   -    | btreemap_v2_contains_blob8_u64               | 277.71M | -16.02% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_contains_blob_8_128              | 268.36M | -16.07% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_insert_u64_blob8                 | 422.66M | -16.13% |  0 | -100.00% |   5 |   0.00% |
|   -    | btreemap_v2_pop_first_u64_u64                | 717.36M | -16.33% |  0 | -100.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_first_u64_vec8               | 709.59M | -16.39% |  0 | -100.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_last_u64_u64                 | 704.61M | -16.41% |  0 | -100.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_first_u64_blob8              | 705.25M | -16.45% |  0 | -100.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_u64_u64                      | 249.27M | -16.71% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_blob_8_128                   | 281.64M | -17.14% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_last_u64_blob8               | 692.89M | -17.20% |  0 | -100.00% |   0 |   0.00% |
|   -    | btreemap_v2_pop_last_u64_vec8                | 696.00M | -17.23% |  0 | -100.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_u64_vec8                     | 246.14M | -17.62% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_get_u64_blob8                    | 245.36M | -17.78% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_contains_u64_u64                 | 236.42M | -18.55% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_scan_keys_rev_1k_0b              | 963.32K | -19.02% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_contains_u64_vec8                | 234.90M | -19.20% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_contains_u64_blob8               | 234.90M | -19.20% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_scan_keys_1k_0b                  | 946.08K | -19.32% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_range_value_sum_1k_0b            |  17.42K | -20.53% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_range_key_sum_1k_0b              |  17.41K | -20.55% |  0 |    0.00% |   0 |   0.00% |
|   -    | btreemap_v2_range_count_1k_0b                |  16.87K | -21.06% |  0 |    0.00% |   0 |   0.00% |

---------------------------------------------------
CSV results saved to canbench_results.csv

[dsarlis]

I would leave a comment why these are disabled for now so that others that stumble upon this code they're not wondering.