Move solution and projects to src

src/Ryujinx.HLE/HOS/Applets/SoftwareKeyboard/InvalidButtonFlags.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace Ryujinx.HLE.HOS.Applets.SoftwareKeyboard
+{
+    /// <summary>
+    /// Identifies prohibited buttons.
+    /// </summary>
+    [Flags]
+    enum InvalidButtonFlags : uint
+    {
+        None         = 0,
+        AnalogStickL = 1 << 1,
+        AnalogStickR = 1 << 2,
+        ZL           = 1 << 3,
+        ZR           = 1 << 4,
+    }
+}