[SPARK-7649] [STREAMING] [WEBUI] Use window.localStorage to store the status rather than the url

Use window.localStorage to store the status rather than the url so that the url won't be changed.

cc tdas

Author: zsxwing <zsxwing@gmail.com>

Closes #6158 from zsxwing/SPARK-7649 and squashes the following commits:

3c56fef [zsxwing] Use window.localStorage to store the status rather than the url