Core/Vehicles: add a way to delay the Vehicle despawn Time if its needed.

* New database table `vehicle_template` holds info for despawn delay with option to extend it in the future

sql/updates/world/master/2020_12_31_00_world.sql

@@ -0,0 +1,9 @@
+--
+-- Table structure for table `vehicle_template`
+--
+DROP TABLE IF EXISTS `vehicle_template`;
+CREATE TABLE `vehicle_template` (
+  `creatureId` int(10) unsigned NOT NULL,
+  `despawnDelayMs` int(11) NOT NULL DEFAULT '0',
+  PRIMARY KEY (`creatureId`)
+) ENGINE=MyISAM;