Add line-backed parameter values with --parameter-file

[220nightmore-spec]

Summary

• add --parameter-file <VAR> <FILE> for using LF- or CRLF-delimited file lines as parameter values
• keep file-backed values and the generated command product lazy, retaining only the active values while commands are executed
• preserve existing --parameter-list Cartesian-product order and allow list/file sources to be interspersed
• reject duplicate parameter names across list and file sources and detect files that change after the initial count pass
• document the option in CLI help, README, and the man page

The initial file pass counts values so command-name and per-command option validation still know the benchmark count. Iteration then reopens the file and reads one line at a time. Benchmark results remain retained as before for comparison and export; this change removes eager retention of the input file values and generated Command product.

Validation

• cargo fmt -- --check
• cargo +1.88.0 clippy --locked --all-targets
• 63 unit tests passed on the declared Rust 1.88 MSRV
• 20 execution-order tests passed, including mixed CRLF file/list product ordering
• 34 Windows-compatible integration tests passed; two existing Unix-shell-specific tests were filtered locally
• cargo +1.88.0 check --locked --target i686-pc-windows-msvc
• cargo build --locked --release
• rendered CLI help assertions for the new option and LF/CRLF behavior
• git diff --check

Fixes #813.

[Scripter17]

Since Sharkdp, the owner of Hyperfine, seems to no longer be maintaining it, I've decided that as long as this PR does what I need it to do and neither of the other two get merged before August 18th, I'll pay out the full bounty to all 3 of the people who've submitted PRs for this.