dev: Added initial version of the grpc api. Added relevant dummy settings to creds (they have no effect rn)

dev: Yt searches now INTERNALLY return multiple results but there is no way right now to paginate plain text results
dev: moved some stuff around

src/NadekoBot/_common/Impl/PubSub/RedisPubSub.cs

@@ -0,0 +1,57 @@
+using StackExchange.Redis;
+
+namespace NadekoBot.Common;
+
+public sealed class RedisPubSub : IPubSub
+{
+    private readonly IBotCredentials _creds;
+    private readonly ConnectionMultiplexer _multi;
+    private readonly ISeria _serializer;
+
+    public RedisPubSub(ConnectionMultiplexer multi, ISeria serializer, IBotCredentials creds)
+    {
+        _multi = multi;
+        _serializer = serializer;
+        _creds = creds;
+    }
+
+    public Task Pub<TData>(in TypedKey<TData> key, TData data)
+        where TData : notnull
+    {
+        var serialized = _serializer.Serialize(data);
+        return _multi.GetSubscriber()
+                     .PublishAsync(new RedisChannel($"{_creds.RedisKey()}:{key.Key}", RedisChannel.PatternMode.Literal),
+                         serialized,
+                         CommandFlags.FireAndForget);
+    }
+
+    public Task Sub<TData>(in TypedKey<TData> key, Func<TData, ValueTask> action)
+        where TData : notnull
+    {
+        var eventName = key.Key;
+
+        async void OnSubscribeHandler(RedisChannel _, RedisValue data)
+        {
+            try
+            {
+                var dataObj = _serializer.Deserialize<TData>(data);
+                if (dataObj is not null)
+                    await action(dataObj);
+                else
+                {
+                    Log.Warning("Publishing event {EventName} with a null value. This is not allowed",
+                        eventName);
+                }
+            }
+            catch (Exception ex)
+            {
+                Log.Error("Error handling the event {EventName}: {ErrorMessage}", eventName, ex.Message);
+            }
+        }
+
+        return _multi.GetSubscriber()
+                     .SubscribeAsync(
+                         new RedisChannel($"{_creds.RedisKey()}:{eventName}", RedisChannel.PatternMode.Literal),
+                         OnSubscribeHandler);
+    }
+}