Controllers: Core: Priority file checking before call API

Make sure if file was exists on the server at first before call any API,
this to prevent long time waiting when batch process task is ongoing.

When file checking logic found not exists file, while compare serve array list
from FE module with existing file on the server. BE will automatically reject task
and return error message. Instead waiting until all other files has processed by
the API.

Signed-off-by: Dicky Herlambang (花） <herlambangdicky5@gmail.com>