core (memory): files are now public by default except for those in root directory:

using public permissions by default makes permissions change more easy as we don't have to
recursively change all permissions of sub files when changing directory. Root directories
are private by default.

sat/memory/memory.py

@@ -1222,7 +1222,15 @@ class Memory(object):
                 perm_data = file_data["access"][perm]
                 perm_type = perm_data["type"]
             except KeyError:
-                raise exceptions.PermissionError()
+                # No permission is set.
+                # If we are in a root file/directory, we deny access
+                # otherwise, we use public permission, as the parent directory will
+                # block anyway, this avoid to have to recursively change permissions for
+                # all sub directories/files when modifying a permission
+                if not file_data.get('parent'):
+                    raise exceptions.PermissionError()
+                else:
+                    perm_type == C.ACCESS_TYPE_PUBLIC
             if perm_type == C.ACCESS_TYPE_PUBLIC:
                 continue
             elif perm_type == C.ACCESS_TYPE_WHITELIST:

sat/memory/sqlite.py

@@ -1426,7 +1426,7 @@ class Updater(object):
         )
         statements.extend([
             f"INSERT INTO files({cols}) SELECT {old_cols} FROM files_old",
-            f"DROP TABLE files_old",
+            "DROP TABLE files_old",
         ])
         statements.extend(Updater.indexData2Raw(index))
         return statements