lib.Distro.default_pkg_filter: Add property

Add a default_pkg_filter parameter to Distro's constructor defaulting
to None, and expose it via the .default_pkg_filter property. As of
this commit, no code in jw-pkg does anything meaningful with it.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/lib/Distro.py

@@ -7,6 +7,7 @@ from functools import cached_property
 
 if TYPE_CHECKING:
     import Iterable
+    from .PackageFilter import PackageFilter
 
 import abc, importlib, re
 
@@ -17,12 +18,19 @@ from .log import *
 
 class Distro(abc.ABC):
 
-    def __init__(self, ec: ExecContext, id: str|None=None, os_release_str: str|None=None):
+    def __init__(
+            self,
+            ec: ExecContext,
+            id: str|None=None,
+            os_release_str: str|None=None,
+            default_pkg_filter: PackageFilter|None=None,
+        ) -> None:
         assert ec is not None
         assert id is not None
         self.__exec_context = ec
-        self.__os_release_str: str|None = os_release_str
         self.__id: str|None = None
+        self.__os_release_str: str|None = os_release_str
+        self.__default_pkg_filter = default_pkg_filter
 
     # Names that can be used by code outside this class to retrieve
     # distribution properties by
@@ -267,6 +275,10 @@ class Distro(abc.ABC):
     def ctx(self) -> ExecContext:
         return self.__exec_context
 
+    @property
+    def default_pkg_filter(self) -> str:
+        return self.__default_pkg_filter
+
     async def run(self, *args, **kwargs) -> Result:
         return await self.__exec_context.run(*args, **kwargs)