[SPARK-15652][LAUNCHER] Added a new State (LOST) for the listeners of SparkLauncher

## What changes were proposed in this pull request?
This situation can happen when the LauncherConnection gets an exception while reading through the socket and terminating silently without notifying making the client/listener think that the job is still in previous state.
The fix force sends a notification to client that the job finished with unknown status and let client handle it accordingly.

## How was this patch tested?
Added a unit test.

Author: Subroto Sanyal <ssanyal@datameer.com>

Closes #13497 from subrotosanyal/SPARK-15652-handle-spark-submit-jvm-crash.