Rewrite the configuration system (#831)

The configuration system was quite fragile and too dependent on everything, this fix #812 .

The changes:

    The file configuration is now entirely independent from the internal configuration state.
    The file configuration is versioned (current version is 1).
    Every configuration elements are now reactive properties that the emulator can register on to handle initialization and configuration changes.
    The configuration system is now in Ryujinx.Common to be accessible on every projects.
    Discord integration is now independent from the UI and can be reloaded.
    The primary controller is now configurable at runtime (NOTE: the UI currently doesn't have any options to configure real controller).
    The logger is entirely reloadable.
    You can now hotplug your controller when the emulator is running.
    The logger now takes name for every LogTarget to make them removable at runtime.
    The logger now always add the default "console" target to avoid loosing early init logs.
    The configuration system now generates a default file configuration if it's missing or too new.
    General system stability improvements to enhance the user's experience

Ryujinx.Common/Configuration/System/Language.cs

@@ -0,0 +1,23 @@
+namespace Ryujinx.Configuration.System
+{
+    public enum Language
+    {
+        Japanese,
+        AmericanEnglish,
+        French,
+        German,
+        Italian,
+        Spanish,
+        Chinese,
+        Korean,
+        Dutch,
+        Portuguese,
+        Russian,
+        Taiwanese,
+        BritishEnglish,
+        CanadianFrench,
+        LatinAmericanSpanish,
+        SimplifiedChinese,
+        TraditionalChinese
+    }
+}