Refactor to benchmark with hyperfine

[privatenumber]

The "hyperfine" tool at https://github.com/sharkdp/hyperfine could be useful for abstracting benchmarking logic. To use it with minifiers lacking CLIs, we'll need to create simple CLI scripts (not difficult). In such cases, the benchmarks will include FS read, but it might have a negligible impact and lead to a fairer comparison, as all minifiers will have to read from the FS, reflecting the performance cost based on runtime choice.