Convert Shlwapi interop code to CSWin32

[elachlan]

Relates to #7445

I am unsure on the SHLoadIndirectString changes and would love some feedback.

In MSBuild, we started with a smaller buffer and looped making it larger if the call failed. Also used ArrayPool in some spots. I guess it really depends on how large the returned information can technically get.

dotnet/msbuild#7186

Microsoft Reviewers: Open in CodeFlow

[elachlan]

Usually most APIs have a length output which makes it possible to quickly ascertain the required length. But some don't and require using a loop and ArrayPool. If we know the max length in advance, this makes it a lot easier.

Example:
https://github.com/dotnet/msbuild/blob/cc2719b701ecf85687b69067bb0a9d9d55344cbe/src/Tasks/ComReference.cs#L407-L436

[elachlan]

@RussKie There is a failure based on the CI image Unable to find directory for cmake 3.21.0;

The test failures I am unsure if they are related or flaky tests?

[RussKie]

No, the CMake is related to the build images and the tooling available in those. The failure was caused by a flaky test.

[RussKie]

LGTM

[lonitra]

Looks good!