Split up test project

Robust.UnitTesting was both ALL tests for RT, and also API surface for content tests.

Tests are now split into separate projects as appropriate, and the API side has also been split off.

Robust.Shared.Tests/RichText/FormattedStringTest.cs

@@ -0,0 +1,54 @@
+using NUnit.Framework;
+using Robust.Shared.RichText;
+
+namespace Robust.UnitTesting.Shared.RichText;
+
+[Parallelizable(ParallelScope.All)]
+[TestOf(typeof(FormattedString))]
+[TestFixture]
+internal sealed class FormattedStringTest
+{
+    /// <summary>
+    /// Test that permissive parsing properly normalizes & passes through markup, as appropriate.
+    /// </summary>
+    [Test]
+    [TestCase("", ExpectedResult = "")]
+    [TestCase("foobar", ExpectedResult = "foobar")]
+    [TestCase("[whaaaaaa", ExpectedResult = "\\[whaaaaaa")]
+    [TestCase("\\[whaaaaaa", ExpectedResult = "\\[whaaaaaa")]
+    [TestCase("[whaaaaaa]wow[/whaaaaaa]", ExpectedResult = "[whaaaaaa]wow[/whaaaaaa]")]
+    [TestCase("[whaaaaaa]\\[womp[/whaaaaaa]", ExpectedResult = "[whaaaaaa]\\[womp[/whaaaaaa]")]
+    public static string TestPermissiveNormalize(string input)
+    {
+        return FormattedString.FromMarkupPermissive(input).Markup;
+    }
+
+    [Test]
+    [TestCase("")]
+    [TestCase("real")]
+    [TestCase("[whaaaaaa]wow[/whaaaaaa]")]
+    public static void TestStrictParse(string input)
+    {
+        var str = FormattedString.FromMarkup(input);
+
+        Assert.That(str.Markup, Is.EqualTo(input));
+    }
+
+    [Test]
+    [TestCase("", ExpectedResult = "")]
+    [TestCase("real", ExpectedResult = "real")]
+    [TestCase("[real", ExpectedResult = "\\[real")]
+    [TestCase("\\", ExpectedResult = @"\\")]
+    public static string TestFromPlainText(string input)
+    {
+        return FormattedString.FromPlainText(input).Markup;
+    }
+
+    [Test]
+    [TestCase("[whaaaaaawow")]
+    [TestCase("[whaaaaaawow val=\"]")]
+    public static void TestStrictThrows(string input)
+    {
+        Assert.That(() => FormattedString.FromMarkup(input), Throws.ArgumentException);
+    }
+}