Moved analyzer tests to its own project

Also moves tests to `./test` which makes it possible
for all test projects to share the same .editorconfig
files and similar.

test/Spectre.Console.Tests/Data/Exceptions.cs

@@ -0,0 +1,35 @@
+using System;
+
+namespace Spectre.Console.Tests.Data
+{
+    public static class TestExceptions
+    {
+        public static bool MethodThatThrows(int? number) => throw new InvalidOperationException("Throwing!");
+
+        public static bool GenericMethodThatThrows<T0, T1, TRet>(int? number) => throw new InvalidOperationException("Throwing!");
+
+        public static void ThrowWithInnerException()
+        {
+            try
+            {
+                MethodThatThrows(null);
+            }
+            catch (Exception ex)
+            {
+                throw new InvalidOperationException("Something threw!", ex);
+            }
+        }
+
+        public static void ThrowWithGenericInnerException()
+        {
+            try
+            {
+                GenericMethodThatThrows<int, float, double>(null);
+            }
+            catch (Exception ex)
+            {
+                throw new InvalidOperationException("Something threw!", ex);
+            }
+        }
+    }
+}