## Summary
As a small quality-of-life improvement, the locator can now slice like
`locator.slice(stmt)` instead of requiring
`locator.slice(stmt.range())`.
## Test Plan
`cargo test`
## Summary
The motivation here is that this enables us to implement `Ranged` in
crates that don't depend on `ruff_python_ast`.
Largely a mechanical refactor with a lot of regex, Clippy help, and
manual fixups.
## Test Plan
`cargo test`
## Summary
If a file has a BOM, the import sorter _always_ reports the imports as
unsorted. The acute issue is that we detect that the line has leading
content (before the imports), which we always consider a violation.
Rather than fixing that one site, this PR instead makes `.line_start`
BOM-aware.
Fixes https://github.com/astral-sh/ruff/issues/6155.
