Core/WorldSession: Add RBAC permission for skipping idle connection check

Port From (https://github.com/TrinityCore/TrinityCore/commit/7625bd960ebc4fab970fb27072aececf9e936e2f)

sql/updates/auth/master/2017_10_13_00_auth.sql

@@ -0,0 +1,7 @@
+DELETE FROM `rbac_permissions` WHERE `id`=7;
+INSERT INTO `rbac_permissions` (`id`,`name`) VALUES
+(7, 'Skip idle connection check');
+
+DELETE FROM `rbac_linked_permissions` WHERE `linkedId`=7;
+INSERT INTO `rbac_linked_permissions` (`id`,`linkedId`) VALUES
+(196,7);