lib.base: Add module

Add lib.base to provide basic definitions.
For now, move the definiions of Result, Input and InputMode from ExecContext into lib.base. Having to import them from the ExecContect module is too heavy-handed for those simple types.
Signed-off-by: Jan Lindemann <jan@janware.com>

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

@@ -7,7 +7,7 @@ from ...Distro import Distro as Base
 
 if TYPE_CHECKING:
     from typing import Iterable
-    from ...ExecContext import Result
+    from ...base import Result
     from ...Package import Package
 
 class Distro(Base):

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

@@ -11,7 +11,7 @@ from ...pm.dpkg import run_dpkg, run_dpkg_query, query_packages, list_files
 
 if TYPE_CHECKING:
     from typing import Iterable
-    from ...ExecContext import Result
+    from ...base import Result
     from ...Package import Package
 
 class Distro(Base):

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

@@ -8,7 +8,7 @@ from ...pm.rpm import run_rpm, query_packages, list_files
 
 if TYPE_CHECKING:
     from typing import Iterable
-    from ...ExecContext import Result
+    from ...base import Result
     from ...Package import Package
 
 class Distro(Base):