Abstract away cache. 2 implementations: redis and memory

src/NadekoBot/Db/Models/StreamOnlineMessage.cs

@@ -0,0 +1,13 @@
+#nullable disable
+using NadekoBot.Services.Database.Models;
+
+namespace NadekoBot.Db.Models;
+
+public class StreamOnlineMessage : DbEntity
+{
+    public ulong ChannelId { get; set; }
+    public ulong MessageId { get; set; }
+
+    public FollowedStream.FType Type { get; set; }
+    public string Name { get; set; }
+}

src/NadekoBot/Db/NadekoContext.cs

@@ -58,6 +58,9 @@ public abstract class NadekoContext : DbContext
     public DbSet<PatronUser> Patrons { get; set; }
 
     public DbSet<PatronQuota> PatronQuotas { get; set; }
+    
+    public DbSet<StreamOnlineMessage> StreamOnlineMessages { get; set; }
+
 
     #region Mandatory Provider-Specific Values