Fix a lot of the analyzer warnings too

MareSynchronos/Services/Mediator/MareMediator.cs

@@ -9,8 +9,8 @@ namespace MareSynchronos.Services.Mediator;
 
 public sealed class MareMediator : IHostedService
 {
-    private readonly object _addRemoveLock = new();
-    private readonly ConcurrentDictionary<object, DateTime> _lastErrorTime = [];
+    private readonly Lock _addRemoveLock = new();
+    private readonly ConcurrentDictionary<SubscriberAction, DateTime> _lastErrorTime = [];
     private readonly ILogger<MareMediator> _logger;
     private readonly CancellationTokenSource _loopCts = new();
     private readonly ConcurrentQueue<MessageBase> _messageQueue = new();