Improve state execution debugability

[longquanzheng]

• separate last_failure --> wait_until_last_failure and execute_last_failure so that they are not overriding
• add separate
  • wait_until_first_attempt_timestamp
  • execute_first_attempt_timestamp
  • wait_until_completed_attempts
  • execute_completed_attempts
  • wait_until_last_attempt_timestamp
  • execute_last_attempt_timestamp
  • wait_until_last_failure
  • execute_last_failure
• Add initiated_state_execution into info field to tell which state initiated this state execution

Also https://github.com/xdblab/xdb/issues/69 https://github.com/xdblab/xdb/issues/43