Investigate a way to allow passing boolean values to the configuration

[avivace]

Because of the current architecture around invenio.cfg and how we load user configuration form the environment, the current way to set a configuration boolean value to false is to set the correspondent environment variable to the python boolean literal "False". I.e., the only way to make a variable read from the environment evaluate to False is to assign it the False string.

This causes problems when such configuration is pushed from a proper serialized format (instead of a python file) such as yaml in helm charts which accept "false" and "False" as boolean falses (but do not cast them back and the lowercase version is more common).

See also: inveniosoftware/helm-invenio#53 inveniosoftware/helm-invenio#54 , where we implemented a workaround on the helm charts to set boolean values to environment and have them correctly parsed as python literals.

A further discussion is needed here to understand if we should:

• switch to a more standard data format to serialize/de-serialize configuration values
• make invenio-config fuzzy match boolean literals
• ...