Custom exception class not used in derived form

Custom exception class not used in derived form

Declare exceptions not per error codes. Just give error code parameter
to the single Csr::Exception class. This architecture is needed for
async client when converting returned error code to exception.

Async scanning client side exception-handling can be done with changed
exception. Callback on exceptional cases(cancelled, error occured) can
be handled in catch statement.

Change-Id: Ic0a0e959fe8e851ea12a09ff9bbcde1ed2659e40
Signed-off-by: Kyungwook Tak <k.tak@samsung.com>