MXS-1220: Unify resource member naming

All resoures now use the `state` member to describe their internal
state. This includes servers, services and monitors. This means that the
`status` keyword can be reserved for something else and it can be removed
until it is needed again.

Changed the module maturity field to `maturity` to better describe its
purpose.

server/core/server.cc

@@ -1412,10 +1412,9 @@ static json_t* server_json_attributes(const SERVER* server)
 
     json_object_set_new(attr, CN_PARAMETERS, params);
 
-
     /** Store general information about the server state */
     char* stat = server_status(server);
-    json_object_set_new(attr, CN_STATUS, json_string(stat));
+    json_object_set_new(attr, CN_STATE, json_string(stat));
     MXS_FREE(stat);
 
     json_object_set_new(attr, CN_VERSION_STRING, json_string(server->version_string));