Issue reporter: use custom dropdown on Windows

[bpasero]

I suggest to use our custom dropdown on Windows for the issue reporter to match the style of dropdowns we have in the workbench:

[cleidigh]

@RMacfarlane
If you need anything on this, let me know.
I can also pick this up if you wish.

[vscodebot]

This issue is being closed to keep the number of issues in our inbox on a manageable level, we are closing issues that are not going to be addressed in the foreseeable future: We look at the number of votes the issue has received and the number of duplicate issues filed. More details here. If you disagree and feel that this issue is crucial: We are happy to listen and to reconsider.

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Thanks for your understanding and happy coding!

[JacksonKearl]

@bpasero I started looking into this and found that using the custom SelectBox widget would introduce a fairly large amount of code bloat:

In short: the Issue Reporter window doesn't have some of the services needed by SelectBox, particularly ContextViewService, which requires a LayoutService. While that can be shimmed to work, we're still left without a styling service. Currently the styles are transferred as query params to the new window, and as the SelectBox builds upon the List widget, it requires a ton of different color keys, which then need to be serialized and deserialized, and all in all it's just a big can of worms.

At that point I consulted with Rachel and we decided this would be more bloat than its worth, additionally, I consulted with @eamodio and the current Windows dropdowns seem stylistically and functionally fine. Unless you feel differently I'm going to close as out of scope.