Fully reverse swkbd configuration structure and follow-up to swkbd implementation (#839)

* am: Fully reverse swkbd configuration structure

* Add documentation

* Remove explicit access modifiers

* Fix formatting

* Fix further formatting issues

Ryujinx.HLE/HOS/Applets/SoftwareKeyboard/InvalidCharFlags.cs

@@ -0,0 +1,56 @@
+using System;
+
+namespace Ryujinx.HLE.HOS.Applets.SoftwareKeyboard
+{
+    /// <summary>
+    /// Identifies prohibited character sets.
+    /// </summary>
+    [Flags]
+    enum InvalidCharFlags : uint
+    {
+        /// <summary>
+        /// No characters are prohibited.
+        /// </summary>
+        None = 0 << 1,
+
+        /// <summary>
+        /// Prohibits spaces.
+        /// </summary>
+        Space = 1 << 1,
+
+        /// <summary>
+        /// Prohibits the at (@) symbol.
+        /// </summary>
+        AtSymbol = 1 << 2,
+
+        /// <summary>
+        /// Prohibits the percent (%) symbol.
+        /// </summary>
+        Percent = 1 << 3,
+
+        /// <summary>
+        /// Prohibits the forward slash (/) symbol.
+        /// </summary>
+        ForwardSlash = 1 << 4,
+
+        /// <summary>
+        /// Prohibits the backward slash (\) symbol.
+        /// </summary>
+        BackSlash = 1 << 5,
+
+        /// <summary>
+        /// Prohibits numbers.
+        /// </summary>
+        Numbers = 1 << 6,
+
+        /// <summary>
+        /// Prohibits characters outside of those allowed in download codes.
+        /// </summary>
+        DownloadCode = 1 << 7,
+
+        /// <summary>
+        /// Prohibits characters outside of those allowed in Mii Nicknames.
+        /// </summary>
+        Username = 1 << 8
+    }
+}