Scripts/Deadmines: move entrance faction spawns to instance_spawn_groups and handle them via faction flags instead

sql/updates/world/4.3.4/2021_07_31_00_world.sql

@@ -0,0 +1,4 @@
+DELETE FROM `instance_spawn_groups` WHERE `spawnGroupId` IN (409, 410);
+INSERT INTO `instance_spawn_groups` (`instanceMapId`, `bossStateId`, `bossStates`, `spawnGroupId`, `flags`) VALUES
+(36, 4, 0x1 | 0x2 | 0x4 | 0x8, 409, 0x1 | 0x4),
+(36, 4, 0x1 | 0x2 | 0x4 | 0x8, 410, 0x1 | 0x8);