Lookup pool name without raising not found exception

If the pool object path is not on the D-Bus, stratisd will not even have
a field for that item in the GetManagedObjects result and will raise an
exception. Do not allow the exception to propagate in this case, but
catch it and return the unknown string.

Signed-off-by: mulhern <amulhern@redhat.com>

Author: mulkieran

src/stratis_cli/_actions/_physical.py

@@ -21,6 +21,9 @@
 # isort: THIRDPARTY
 from justbytes import Range
 
+# isort: FIRSTPARTY
+from dbus_client_gen import DbusClientMissingPropertyError
+
 from .._stratisd_constants import BlockDevTiers
 from ._connection import get_object
 from ._constants import TOP_OBJECT
@@ -79,6 +82,16 @@ def list_devices(namespace: Namespace):  # pylint: disable=too-many-locals
             ).search(managed_objects)
         )
 
+        def pool_name_lookup(modev) -> str:
+            """
+            Look up a name for a pool. Return place holder if the modev
+            has no pool attribute.
+            """
+            try:
+                return path_to_name.get(modev.Pool(), TABLE_UNKNOWN_STRING)
+            except DbusClientMissingPropertyError:
+                return TABLE_UNKNOWN_STRING
+
         def paths(modev):
             """
             Return <physical_path> (<metadata_path>) if they are different,
@@ -126,7 +139,7 @@ def tier_str(value):
 
         tables = [
             [
-                path_to_name.get(modev.Pool(), TABLE_UNKNOWN_STRING),
+                pool_name_lookup(modev),
                 paths(modev),
                 size(modev),
                 tier_str(modev.Tier()),