feat(vector): add index operations without bounds checks

[vapourismo]

What

Adds two methods to the Vector state components:

• index_unchecked
• index_unchecked_mut

These two methods allow you to obtain references to the underlying elements without incurring the cost of a bounds check.

Why

These functions are important for the usage of this state component in performance critical contexts.
See #962 for usage of these methods.

Manually Testing

make all

Tasks for the Author

• Link all Linear issues related to this MR using magic words (e.g. part of, relates to, closes).
• Eliminate dead code and other spurious artefacts introduced in your changes.
• Document new public functions, methods and types.
• Make sure the documentation for updated functions, methods, and types is correct.
• Add tests for bugs that have been fixed.
• Explain changes to regression test captures when applicable.
• Write commit messages in agreement with our guidelines.
• Self-review your changes to ensure they are high-quality.
• Complete all of the above before assigning this MR to reviewers.

[github-actions]

Benchmark results for revision 6994cb8:

Metric	Duration	TPS
Mean	1.520093416s	26.314
Worst	1.527196133s	26.192
Best	1.511172514s	26.470
Standard Deviation	±4.645999ms	±0.080

Full results

Run	Transfers	Duration	TPS
1	40	1.52693015s	26.196
2	40	1.52415024s	26.244
3	40	1.527145634s	26.193
4	40	1.515689623s	26.391
5	40	1.516332663s	26.379
6	40	1.520083014s	26.314
7	40	1.511172514s	26.470
8	40	1.51738434s	26.361
9	40	1.521296641s	26.293
10	40	1.527048926s	26.194
11	40	1.512085967s	26.454
12	40	1.52197925s	26.282
13	40	1.517228748s	26.364
14	40	1.527196133s	26.192
15	40	1.516944s	26.369
16	40	1.519261533s	26.329
17	40	1.517786692s	26.354
18	40	1.519825054s	26.319
19	40	1.519773727s	26.320
20	40	1.522553477s	26.272

Compare the results above with those for the default branch.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 24 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.74%. Comparing base (9b1c76e) to head (5d706a2).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
data/src/components/vector.rs	0.00%	24 Missing ⚠️

❌ Your patch status has failed because the patch coverage (0.00%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #963      +/-   ##
==========================================
- Coverage   89.87%   89.74%   -0.14%     
==========================================
  Files         110      110              
  Lines       22084    22108      +24     
  Branches    22084    22108      +24     
==========================================
- Hits        19848    19840       -8     
- Misses       1837     1869      +32     
  Partials      399      399              

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