Added unit to logs getter

Signed-off-by: Dmitry Anurin <d.anurin@yadro.com>

src/frostfs_testlib/hosting/interfaces.py

@@ -257,6 +257,7 @@ class Host(ABC):
         message_regex: str,
         since: Optional[datetime] = None,
         until: Optional[datetime] = None,
+        unit: Optional[str] = None,
     ) -> bool:
         """Checks logs on host for specified message regex.