windows: Add file dialog using IFileOpenDialog

[the-jasoney]

Release Notes:

• Added a file dialog for Windows

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[the-jasoney]

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[mikayla-maki]

Could you include a screenshot of the working file dialog as well?

[the-jasoney]

[mikayla-maki]

I notice that this part of another PR initializes COM for the length of the app, through a different API. Could we use that approach instead? Or is there a compelling reason to keep the approach you're using?

[mikayla-maki]

Once the COM initialization is figured out, and the merge conflicts resolved, I think I'd prefer to merge this one as it looks a little nicer.

[the-jasoney]

I notice that this part of another PR initializes COM for the length of the app, through a different API. Could we use that approach instead? Or is there a compelling reason to keep the approach you're using?

I'm pretty sure the approach in the PR would work.

[mikayla-maki]

@the-jasoney when the merge conflicts are resolved, I'd be down to merge this :)

[JunkuiZhang]

Once the COM initialization is figured out, and the merge conflicts resolved, I think I'd prefer to merge this one as it looks a little nicer.

The CoInitialize stuff can be deleted, by Microsoft:

OleInitialize calls CoInitializeEx internally to initialize the COM library on the current apartment.

And since the COM library is initialized on an apartment only once, CoInitialize using in this PR actually does nothing. See Microsoft's comments:

Typically, the COM library is initialized on an apartment only once. Subsequent calls will succeed, as long as they do not attempt to change the concurrency model of the apartment, but will return S_FALSE.

Edit: In my previous PR #8809 , actually use OleInitialize with IFileOpenDialog, IFileSaveDialog and IDropTarget, and all works fine.

[mikayla-maki]

Now that #8959 has been merged, we should get this branch up to date with main and remove the COM initialization / tear down. Then we can merge :)

[mikayla-maki]

Seems this needs another merge conflict resolution, and a cargo fmt before we can merge it :)