Send frame done to floating views

Also centers them on the screen when initially floated

In the future we'll need a more sophisticated solution than that

sway/ipc-json.c

@@ -21,8 +21,6 @@ static const char *ipc_json_layout_description(enum sway_container_layout l) {
 		return "tabbed";
 	case L_STACKED:
 		return "stacked";
-	case L_FLOATING:
-		return "floating";
 	case L_NONE:
 		break;
 	}