Add a base config schema that provides quantities support

This schema is provided to use as a default, and might be extended in
the future to support more commonly used fields that are not provided
by marshmallow by default.

To use the quantity schema we need to bump the `frequenz-quantities`
dependency and add the optional `marshmallow` dependency.

Signed-off-by: Leandro Lucarella <luca-frequenz@llucax.com>

pyproject.toml

@@ -31,7 +31,7 @@ dependencies = [
   # (plugins.mkdocstrings.handlers.python.import)
   "frequenz-client-microgrid >= 0.6.0, < 0.7.0",
   "frequenz-channels >= 1.4.0, < 2.0.0",
-  "frequenz-quantities >= 1.0.0rc3, < 2.0.0",
+  "frequenz-quantities[marshmallow] >= 1.0.0, < 2.0.0",
   "networkx >= 2.8, < 4",
   "numpy >= 1.26.4, < 2",
   "typing_extensions >= 4.6.1, < 5",

src/frequenz/sdk/config/_base_schema.py

@@ -0,0 +1,10 @@
+# License: MIT
+# Copyright © 2024 Frequenz Energy-as-a-Service GmbH
+
+"""Base schema for configuration classes."""
+
+from frequenz.quantities.experimental.marshmallow import QuantitySchema
+
+
+class BaseConfigSchema(QuantitySchema):
+    """A base schema for configuration classes."""