Chiapos

Added
- F1 generation is now fully parallel for a small speedup.
- We have bitfield optimized phase 2. There is only about a 1% increase in speed from this change but there is a 12% decrease in writes with a penalty of 3% more reads. More details in [PR 120](https://github.com/Chia-Network/chiapos/pull/120)
- You can now build chiapos with Cmake and MSVC. We know build and test C++ for Windows as well as create and test Windows wheels.

Changed
- We have moved from using gulrak/filesystem across all platforms to only using it on MacOS. It's required on MacOS as we are still targeting Mojave compatibility. This should resolve Windows path issues.
- Various pointers and memory management were modernized.

Fixed
- Starting with recent setuptools fixes, we can no longer pass an empty string to the linker on Windows when building binary wheels. Thanks jaraco for tracking this down.

Fixed
- When fixing a possible problem with reading past a buffer, we slowed down total performance by about 20%. This has an alternative fix that should maintain 0.12.31/Beta 15's plotting speed - if not speed up some based on other improvements in 0.12.32.
- Certain NTFS mount points could cause an error in gulrak/filesystem. We've implemented a patch and upstreamed the issue. See https://github.com/gulrak/filesystem/issues/75
- Added additional plotting testing to GitHub Actions
- Separated out the C++ build/test workflow from the Ubuntu wheel build and test.

Added
- Significant speed ups to F1 plotting.
- You can now log disk I/O and there is a gnuplot script to plot disk usage.

Changed
- The command to ProofOfSpace is now `create` instead of `generate` to align with chia-blockchain.
- pep517.build was deprecated on the ci build.
- A plethora of memory management, code readability, and compute efficiencies were improved.
- Various unused code was removed.
- C++ tests were added to the default cmake build process.

Fixed
- There was an out of bounds read that could crash the plotter in SliceInt64FromBytes().
- gulrak/filesystem was updated to 1.3.6 and it should address certain writing failures on windows around the case of the drive letter. See https://github.com/gulrak/filesystem/issues/70

Fixes a bug introduced in Beta 1.8 that could cause a buffer overrun on larger k size plots.

don't keep file handles open as we might exceed OS limits

better error handling for reads and writes