I originally added these platforms to prevent the .NET components from
building when you built the entire solution, and to prevent them from
building in CI.
It turns out that managing an extra thousand project-platform-config
triples is an absolute pain, **and** that we should have been building
these things in CI the entire time. So.
This should make life _a lot_ easier.
As a bonus, this PR enables the WPF test harness to build for ARM64.
This gets rid of warnings like
```
NU1102: Unable to find package Microsoft.NETCore.App.Host.win-x64 with version (= 3.1.21)
- Found 1 version(s) in TerminalDependencies [ Nearest version: 3.1.18 ]
```
Technically, there's a `NETCore.App.Host.3.1.21` that's out now. We _could_
migrate to that, but then we'd have to make sure to manually re-upload that
nuget package to our nuget feed, and then we'd still get this warning the
next time that package is updated.
Theoretically, there's a 6.x version too, but considering this is a debugging
tool, we don't care all that much.
* [x] I work here
* [x] Discussed this with Dustin
* [x] Gets rid of a SUPER TRIVIAL warning.
As VS 2022 doesn't seem to store files with UTF-8 BOM as often anymore, we've
been getting more and more pull requests which seemingly randomly change files.
This cleans the situation up by removing the BOM from all files that have one.
Additionally, `Host.Tests.Feature.rc` was converted from UTF-16 to UTF-8.
There were some minor annoyances with the WPF projects.
1. WpfTerminalTestNetCore was in an unnecessary same-named subdirectory
2. The build started throwing deprecation warnings because `netcoreapp3.0` is not LTS and is going away.
