dc01cbc538 test: Add fs_tests/rename unit test (Hennadii Stepanov)
d4999d40b9 util: Revert back MoveFileExW call for MinGW-w64 (Hennadii Stepanov)
Pull request description:
Unfortunately, bitcoin/bitcoin#24308 introduced a [regression](https://github.com/bitcoin/bitcoin/pull/24308#issuecomment-1037259386) for mingw builds.
The root of the problem is a broken implementation of [`std::filesystem::rename`](https://en.cppreference.com/w/cpp/filesystem/rename). In particular, the expected behavior
> If `old_p` is a non-directory file, then `new_p` must be ... existing non-directory file: `new_p` _is first deleted_...
fails with the "File exists" error.
This PR reverts back the `MoveFileExW` call, and adds the [suggested](https://github.com/bitcoin/bitcoin/pull/24308#pullrequestreview-878832906) unit test.
ACKs for top commit:
vasild:
ACK dc01cbc538
Tree-SHA512: c8e5a98844cfa32bec0ad67a1aaa58fe2efd0c5474d3e83490211985b110f83245758a742dcaa0a933a192ab66a7f11807e0c53ae69260b7dd02fc99f6d03849
df0825046a