Feature: various: remove isolation wrapper support

Including:

• the isolation-instance, isolation-wrapper, isolation-host, and isolation resource meta-attributes
• Public API symbols: XML_RSC_ATTR_ISOLATION_INSTANCE, XML_RSC_ATTR_ISOLATION_WRAPPER, XML_RSC_ATTR_ISOLATION_HOST, XML_RSC_ATTR_ISOLATION, resource_t isolation_wrapper member

Isolation wrappers were obsoleted by bundle resources. This breaks rolling
upgrades from Pacemaker 1.x clusters that used isolation wrappers.