[#252] add filter priority to get_filtered_logs method

src/frostfs_testlib/hosting/interfaces.py

@@ -297,6 +297,7 @@ class Host(ABC):
         until: Optional[datetime] = None,
         unit: Optional[str] = None,
         exclude_filter: Optional[str] = None,
+        priority: Optional[str] = None
     ) -> str:
         """Get logs from host filtered by regex.
 
@@ -305,6 +306,8 @@ class Host(ABC):
             since: If set, limits the time from which logs should be collected. Must be in UTC.
             until: If set, limits the time until which logs should be collected. Must be in UTC.
             unit: required unit.
+            priority: logs level, 0 - emergency, 7 - debug. All messages with that code and higher. 
+            For example, if we specify the -p 2 option, journalctl will show all messages with levels 2, 1 and 0.
 
         Returns:
             Found entries as str if any found.