Use a wrapper with unbuffered I/O for farming on Windows

[nazar-pc]

This PR makes farming on Windows use unbuffered I/O, which avoids memory usage issues, but also has annoying alignment requirements. Users are testing this on the forum already.

Since reads we're doing during farming are tiny, I didn't implement fast path for cases where both read target and memory buffer into which read bytes are written are already aligned (it will not be a typical case for farming anyway), but that could be a hypothetical improvement.

Farming is a fairly limited in scope code path, so it was relatively easy to add there. We do have other places where reads are doing the old way though and I think there will be value of expanding there as well (left TODO about this). We can replace the whole File with this UnbufferedIoFileWindows for both reads and writes a bit later by implementing FileExt on it, but this PR should already be a huge improvement as is.

PR includes a few basic tests with aligned and unaligned reads that are cross-platform for convenience, but UnbufferedIoFileWindows only makes sense to use on Windows due to unnecessary copying on other platforms that do not suffer from memory usage bugs in the first place.

I also noticed a bit better auditing and proving performance with these changes (nothing to phone home about, but still), which are not very surprising.

Code contributor checklist:

• I have read, understood and followed contributing guide

[nazar-pc]

Not great feedback here on farming success, so converting to draft for now

[nazar-pc]

Added workarounds for more Windows bugs, specifically al8n/fs4-rs#13 (https://learn.microsoft.com/en-us/answers/questions/1608540/getfileinformationbyhandle-followed-by-read-with-f), should work this time 🤞

[nazar-pc]

Farmers confirm latest revision I just pushed finally seems to work, even though it is a pile of Windows-specific hacks.

[nazar-pc]

Next steps:

• use new wrapper for all reads
• likely expose reading of the whole sector as a CLI option