Added and applied styles for private readonly fields, private fields to Extensions and Common folders.

- Some renamings and code cleanups
- Chained method calls, binary expressions and binary patterns will now break into newlines
- Type param constraints and base constructor calls will be on the new line

src/NadekoBot/_Extensions/BotCredentialsExtensions.cs

@@ -0,0 +1,7 @@
+namespace NadekoBot.Extensions;
+
+public static class BotCredentialsExtensions
+{
+    public static bool IsOwner(this IBotCredentials creds, IUser user)
+        => creds.OwnerIds.Contains(user.Id);
+}

src/NadekoBot/_Extensions/ServiceCollectionExtensions.cs

@@ -0,0 +1,73 @@
+using System.Reflection;
+using Microsoft.Extensions.DependencyInjection;
+using NadekoBot.Modules.Music;
+using NadekoBot.Modules.Music.Resolvers;
+using NadekoBot.Modules.Music.Services;
+using StackExchange.Redis;
+
+namespace NadekoBot.Extensions;
+
+public static class ServiceCollectionExtensions
+{
+    public static IServiceCollection AddBotStringsServices(this IServiceCollection services, int totalShards)
+        => totalShards <= 1
+            ? services.AddSingleton<IStringsSource, LocalFileStringsSource>()
+                .AddSingleton<IBotStringsProvider, LocalBotStringsProvider>()
+                .AddSingleton<IBotStrings, BotStrings>()
+            : services.AddSingleton<IStringsSource, LocalFileStringsSource>()
+                .AddSingleton<IBotStringsProvider, RedisBotStringsProvider>()
+                .AddSingleton<IBotStrings, BotStrings>();
+
+    public static IServiceCollection AddConfigServices(this IServiceCollection services)
+    {
+        var baseType = typeof(ConfigServiceBase<>);
+
+        foreach (var type in Assembly.GetCallingAssembly().ExportedTypes.Where(x => x.IsSealed))
+        {
+            if (type.BaseType?.IsGenericType == true &&
+                type.BaseType.GetGenericTypeDefinition() == baseType)
+            {
+                services.AddSingleton(type);
+                services.AddSingleton(x => (IConfigService)x.GetRequiredService(type));
+            }
+        }
+
+        return services;
+    }
+
+    public static IServiceCollection AddConfigMigrators(this IServiceCollection services)
+        => services.AddSealedSubclassesOf(typeof(IConfigMigrator));
+
+    public static IServiceCollection AddMusic(this IServiceCollection services)
+        => services.AddSingleton<IMusicService, MusicService>()
+            .AddSingleton<ITrackResolveProvider, TrackResolveProvider>()
+            .AddSingleton<IYoutubeResolver, YtdlYoutubeResolver>()
+            .AddSingleton<ISoundcloudResolver, SoundcloudResolver>()
+            .AddSingleton<ILocalTrackResolver, LocalTrackResolver>()
+            .AddSingleton<IRadioResolver, RadioResolver>()
+            .AddSingleton<ITrackCacher, RedisTrackCacher>()
+            .AddSingleton<YtLoader>()
+            .AddSingleton<IPlaceholderProvider>(svc => svc.GetRequiredService<IMusicService>());
+
+    // consider using scrutor, because slightly different versions
+    // of this might be needed in several different places
+    public static IServiceCollection AddSealedSubclassesOf(this IServiceCollection services, Type baseType)
+    {
+        var subTypes = Assembly.GetCallingAssembly()
+            .ExportedTypes.Where(type => type.IsSealed && baseType.IsAssignableFrom(type));
+
+        foreach (var subType in subTypes)
+        {
+            services.AddSingleton(baseType, subType);
+        }
+
+        return services;
+    }
+
+    public static IServiceCollection AddRedis(this IServiceCollection services, string redisOptions)
+    {
+        var conf = ConfigurationOptions.Parse(redisOptions);
+        services.AddSingleton(ConnectionMultiplexer.Connect(conf));
+        return services;
+    }
+}