[usecase-webapi] Improve time usecase

- Change the date/time display to table.
- Put year/month/day in same line, h/m/s in another line.

Impacted TCs num(approved): New 0, Update 1, Delete 0
Unit test Platform: [Tizen-IVI]
Test result summary: Pass 1, Fail 0, Blocked 0
Merge pull request #621 from JianfengXu/xujf/time/update

[usecase-webapi] Improve time usecase