[SPARK-4166][Core][WebUI] Display the executor ID in the Web UI when ExecutorLostFailure happens

Now when ExecutorLostFailure happens, it only displays `ExecutorLostFailure (executor lost)`. Adding the executor id will help locate the faulted executor.

Author: zsxwing <zsxwing@gmail.com>

Closes #3033 from zsxwing/SPARK-4166 and squashes the following commits:

ff4664c [zsxwing] Backward-compatible support
c5c4cf2 [zsxwing] Display the executor ID in the Web UI when ExecutorLostFailure happens