rgw: sync with elastic search v7

rgw: sync with elastic search v7

elastic search removes mapping types feature. see
https://www.elastic.co/guide/en/elasticsearch/reference/current/removal-of-types.html

to support elastic search above 7.0, es sync module includes following
changes :

1. the ElasticConfig struct addes new member "esinfo";
2. create elastic index without root type "object";
3. upload elastic document with new typeless path "/_doc/{id}";
4. add new exist error code "resource_already_exists_exception".

Fixes: https://tracker.ceph.com/issues/41227
Signed-off-by: Chang Liu <liuchang0812@gmail.com>
(cherry picked from commit c39761cddacbc82f70805b36e15970044c1a5d9c)

Conflicts:
	src/rgw/rgw_sync_module_es.cc
- svc.zone
- get_cr_registry