Migrate to new .csproj format

[YoshiRulz]

edit 2024-04-26:
I recreated my changes on top of the latest commit, taking a slightly different approach. This time I haven't had the chance to test on a Windows machine.
I kept a backup of the old branch.

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Guess I'm done? Wasn't expecting CI to pass with only a couple of tweaks. Builds and runs on my Win10 machine with VS2022.

Didn't expect it to magically work in Mono, and it doesn't, failing with Could not load file or assembly 'PresentationCore, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. (part of WPF I gather).

see #72 (comment)

[danebou]

Is the Resource directory copy handled? Before: <PreBuildEvent>xcopy /E /Y /I "$(ProjectDir)Resources" "$(TargetDir)Resources" /D</PreBuildEvent>

[danebou]

Is the Resource directory copy handled? Before: <PreBuildEvent>xcopy /E /Y /I "$(ProjectDir)Resources" "$(TargetDir)Resources" /D</PreBuildEvent>

Yes it is

[danebou]

Sorry, forgot about your PR and made some more merge conflicts with recent changes. Can you resolve them? I'll try to keep these files untouched in the meantime.

[YoshiRulz]

Please don't make me do that again.

edit: I should add that 440f632 starts a divide-and-conquer, but I don't actually finish the conquer part in this PR. That's partially because I can't glob if only some files have a property, but also I've been meaning to investigate a programmatic solution to marking those Designer files but haven't gotten around to it.

[danebou]

Thanks. That'd be nice if there was a clean way to handle those.

[YoshiRulz]

"Clean" and "the WinForms Designer" are mutually exclusive, I've found.

This was good then? Nothing broke? The next thing I wanted to do was take a look at what tests you have, hopefully get them running without code changes.