Test: enhancing log behaviors for unittest

Test: enhancing log behaviors for unittest

1. Add a dlog_print hijacker that makes dlog calls independent
from dlog daemon and drivers. As a result, developers can now
read the dlog log messages of unittests in gbs environment.

2. Clean up a bit of meson.build dependency declaration of
unit tests.

3. A unit test without direct dlog call is updated to call
it directly so that the hijacker is linked (edgetpu).

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>