Medusa System Added

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

src/NadekoBot/Common/Medusa/Models/ParamData.cs

@@ -0,0 +1,9 @@
+namespace Nadeko.Medusa;
+
+public sealed record ParamData(
+    Type Type,
+    string Name,
+    bool IsOptional,
+    bool IsLeftover,
+    bool IsParams
+);

src/NadekoBot/Common/Medusa/Models/ResolvedMedusa.cs

@@ -0,0 +1,14 @@
+using System.Collections.Immutable;
+
+namespace Nadeko.Medusa;
+
+public sealed record ResolvedMedusa(
+    WeakReference<MedusaAssemblyLoadContext> LoadContext,
+    IImmutableList<ModuleInfo> ModuleInfos,
+    IImmutableList<SnekInfo> SnekInfos,
+    IMedusaStrings Strings,
+    Dictionary<Type, TypeReader> TypeReaders,
+    IReadOnlyCollection<ICustomBehavior> Execs)
+{
+    public IServiceProvider Services { get; set; } = null!;
+}

src/NadekoBot/Common/Medusa/Models/SnekCommandData.cs

@@ -0,0 +1,41 @@
+using Microsoft.VisualBasic;
+using System.Reflection;
+using CommandStrings = Nadeko.Snake.CommandStrings;
+
+namespace Nadeko.Medusa;
+
+public sealed class SnekCommandData
+{
+    public SnekCommandData(
+        IReadOnlyCollection<string> aliases,
+        MethodInfo methodInfo,
+        Snek module,
+        FilterAttribute[] filters,
+        CommandContextType contextType,
+        IReadOnlyList<Type> injectedParams,
+        IReadOnlyList<ParamData> parameters,
+        CommandStrings strings,
+        int priority)
+    {
+        Aliases = aliases;
+        MethodInfo = methodInfo;
+        Module = module;
+        Filters = filters;
+        ContextType = contextType;
+        InjectedParams = injectedParams;
+        Parameters = parameters;
+        Priority = priority;
+        OptionalStrings = strings;
+    }
+
+    public CommandStrings OptionalStrings { get; set; }
+
+    public IReadOnlyCollection<string> Aliases { get; }
+    public MethodInfo MethodInfo { get; set; }
+    public Snek Module { get; set; }
+    public FilterAttribute[] Filters { get; set; }
+    public CommandContextType ContextType { get; }
+    public IReadOnlyList<Type> InjectedParams { get; }
+    public IReadOnlyList<ParamData> Parameters { get; }
+    public int Priority { get; }
+}

src/NadekoBot/Common/Medusa/Models/SnekData.cs

@@ -0,0 +1,11 @@
+namespace Nadeko.Medusa;
+
+public sealed record SnekInfo(
+    string Name,
+    SnekInfo? Parent,
+    Snek Instance,
+    IReadOnlyCollection<SnekCommandData> Commands,
+    IReadOnlyCollection<FilterAttribute> Filters)
+{
+    public List<SnekInfo> Subsneks { get; set; } = new();
+}