[Quest API] Add EVENT_COMBINE to Perl and Lua. (#1536)

- Exports $container_slot in Perl.
- Exports e.container_slot in Lua.

Allows you to perform events when clicking combine in a tradeskill container.

zone/embparser.cpp

@@ -122,6 +122,7 @@ const char *QuestEventSubroutines[_LargestEventID] = {
 	"EVENT_BOT_COMMAND",
 	"EVENT_WARP",
 	"EVENT_TEST_BUFF",
+	"EVENT_COMBINE",
 	"EVENT_CONSIDER",
 	"EVENT_CONSIDER_CORPSE"
 };
@@ -1657,6 +1658,11 @@ void PerlembParser::ExportEventVariables(
 			break;
 		}
 
+		case EVENT_COMBINE: {
+			ExportVar(package_name.c_str(), "container_slot", std::stoi(data));
+			break;
+		}
+
 		default: {
 			break;
 		}