[User] implement sm_user_get_service_all API
[Refactor] remove root_value null checking, and type checking, and label 'json_parse_failure'

json_value_get_type, and json_value_get_object will check the NULL and JSON type for us.
[Refactor] define _return to replace return, add do memory free in label _return
[Refactor] add modifier 'const' to 'sm_user_digest_login' parameters 'username' and 'password'
[Util] implement internal function 'sm_crypto_SHA1' and 'sm_generate_api_token'
[Service] implement sm_mec_send_message API

* define enum SM_MQTT_OQS, SM_MQTT_SEND_TYPE