Open only one database per process

:Release Notes:
Service db8 serve only one database per process

:Detailed Notes:
Remove opening of tempdb and mediadb from MojServiceApp
Move to configuration file database path. db -> path
Move to configuration file service name: db -> service_name

:Testing Performed:
Compiled and tested localy

:QA Notes:

:Issues Addressed:

Open-webOS-DCO-1.0-Signed-off-by: Maksym Sditanov <maxim.sditanov@lge.com>