Adds more tests, fixes

Plugins/PkmnLib.Plugin.Gen7.Tests/TestFailingAttribute.cs

@@ -0,0 +1,9 @@
+namespace PkmnLib.Plugin.Gen7.Tests;
+
+/// <summary>
+/// Marks a test as known to be failing, so that it will be skipped when running all tests, while still allowing us
+/// to know that we should still fix it.
+/// </summary>
+public class TestFailingAttribute(string failureReason) : SkipAttribute("Test is currently failing: " + failureReason)
+{
+}