Incorrect api used for sys_read_dir on windows #315
Description
On windows, neko uses FindFirstFileA for sys_read_dir. This returns ANSI encoded strings (not to be confused with ASCII) which means that any non-ascii characters are not compatible with utf8, so they can cause issues when the strings from this function are passed to other places.
We should instead use the FindFirstFileW variant which gives utf-16 encoded strings, which can then be converted to valid utf-8.
Similarly, we should replace any use of ANSI variants of the windows api.
This way the behaviour will match non-windows platforms and be more compatible.