Use `arcstr` for package, extra, and group names (#10475)
## Summary
This appears to be a consistent 1% performance improvement and should
also reduce memory quite a bit. We've also decided to use these for
markers, so it's nice to use the same optimization here.
```
❯ hyperfine "./uv pip compile --universal scripts/requirements/airflow.in" "./arcstr pip compile --universal scripts/requirements/airflow.in" --min-runs 50 --warmup 20
Benchmark 1: ./uv pip compile --universal scripts/requirements/airflow.in
Time (mean ± σ): 136.3 ms ± 4.0 ms [User: 139.1 ms, System: 241.9 ms]
Range (min … max): 131.5 ms … 149.5 ms 50 runs
Benchmark 2: ./arcstr pip compile --universal scripts/requirements/airflow.in
Time (mean ± σ): 134.9 ms ± 3.2 ms [User: 137.6 ms, System: 239.0 ms]
Range (min … max): 130.1 ms … 151.8 ms 50 runs
Summary
./arcstr pip compile --universal scripts/requirements/airflow.in ran
1.01 ± 0.04 times faster than ./uv pip compile --universal scripts/requirements/airflow.in
```
