Medusa System Added

Read about the medusa system [here](https://nadekobot.readthedocs.io/en/latest/medusa/creating-a-medusa/)

src/NadekoBot/Common/Medusa/Adapters/DmContextAdapter.cs

@@ -0,0 +1,48 @@
+using Microsoft.Extensions.DependencyInjection;
+
+public sealed class DmContextAdapter : DmContext
+{
+    public override IMedusaStrings Strings { get; }
+    public override IDMChannel Channel { get; }
+    public override IUserMessage Message { get; }
+    public override IUser User
+        => Message.Author;
+    
+    private readonly IServiceProvider _services;
+    private readonly Lazy<IEmbedBuilderService> _ebs;
+    private readonly Lazy<IBotStrings> _botStrings;
+    private readonly Lazy<ILocalization> _localization;
+
+    public DmContextAdapter(ICommandContext ctx, IMedusaStrings strings, IServiceProvider services)
+    {
+        if (ctx is not { Channel: IDMChannel ch })
+        {
+            throw new ArgumentException("Can't use non-dm context to create DmContextAdapter", nameof(ctx));
+        }
+
+        Strings = strings;
+
+        _services = services;
+
+        Channel = ch;
+        Message = ctx.Message;
+        
+        
+        _ebs = new(_services.GetRequiredService<IEmbedBuilderService>());
+        _botStrings = new(_services.GetRequiredService<IBotStrings>);
+        _localization = new(_services.GetRequiredService<ILocalization>());
+    }
+
+    public override IEmbedBuilder Embed()
+        => _ebs.Value.Create();
+
+    public override string GetText(string key, object[]? args = null)
+    {
+        var cultureInfo = _localization.Value.GetCultureInfo(default(ulong?));
+        var output = Strings.GetText(key, cultureInfo, args ?? Array.Empty<object>());
+        if (!string.IsNullOrWhiteSpace(output))
+            return output;
+        
+        return _botStrings.Value.GetText(key, cultureInfo, args);
+    }
+}