Replaced multiple file writes with a single string template write.
The raw content is first grouped into 8 byte chunks, followed by another regex replace which wraps them in `std::byte`.
Tested the output with `diff -w` and they're the same - only whitespace differences because slightly different source formatting.
Tested the performance with:
> time cmake -DRAW_SOURCE_PATH=src/bench/data/block413567.raw -DHEADER_PATH=build/after/block413567.raw.h -DRAW_NAMESPACE=benchmark::data -P cmake/script/GenerateHeaderFromRaw.cmake
Before:
> 15.41s user 23.06s system 97% cpu 39.593 total
After:
> 0.77s user 0.06s system 97% cpu 0.849 total
This change allows to drop brittle sizeof calls in favor of the
std::span::size method.
Other improvements include:
* Use of a namespace to mark test and bench data
* Use of the modern std::byte
* Drop of a no longer used std::vector copy and the bench/data module
