add: Added .cleanupguilddata command which will delete all guildconfigs, xp stats and other data related to any guild the bot is no longer in. This is a highly destructive and irreversible command.

dev: Added cascade deletes to any tables which have guildconfigs FK, as well as to some other missing places

src/NadekoBot/Migrations/MigrationQueries.cs

@@ -1,5 +1,6 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Migrations;
+using NadekoBot.Db.Models;
 
 namespace NadekoBot.Migrations;
 
@@ -39,4 +40,15 @@ left join guildconfigs on reactionrolemessage.guildconfigid = guildconfigs.id;")
             throw new NotSupportedException("This database provider doesn't have an implementation for MigrateRero");
         }
     }
+
+    public static void GuildConfigCleanup(MigrationBuilder builder)
+    {
+        builder.Sql($"""
+                     DELETE FROM "StreamRoleBlacklistedUser" WHERE "StreamRoleSettingsId" is NULL;
+                     """);
+
+        builder.Sql($"""
+                     DELETE FROM "DelMsgOnCmdChannel" WHERE "GuildConfigId" is NULL;
+                     """);
+    }
 }