https client for es syntax and meta data enhancement

[critical27]

In #3150 we have supported https client for es, but the syntax is weird:

SIGN IN TEXT SERVICE (127.0.0.1:9200, HTTP);
SIGN IN TEXT SERVICE (127.0.0.1:9200, HTTP, "user", "password");
SIGN IN TEXT SERVICE (127.0.0.1:9200, HTTPS, "user", "password");

Actually, we could simplify the syntax as belows, which involve a meta format change, see #3150 (comment) for details:

SIGN IN TEXT SERVICE 
  (http://127.0.0.1:9200, "user", "password"),
  (https://127.0.0.1:9200, "user", "password")