…TODO about using real JSON

…static for reuse in OIDC factory

…provider configuration.

Before this refactoring, a static list of providers has been used, no matter if they where
enabled or not. This is not acceptable for the new OIDC provider, as we might have multiple
of 'em and it retrieves metadata on creation.

So the idea was to not create some static list of IDs (which had been used to look up the real
provider from the "registry"), but instead get the registred providers, sort them and
retrieve the display info.

Sorting is done by a numerical value first, then by id attribute (which is set by factories),
so we have a deterministic, unchanging order for the user.

This lead to the creation of a new method AuthenticationProvider.getOrder(), defaulting to 1
and overridden by implementations. This opens up the possibility to change ordering by
configuration (as suggested in an old TODO comment of the refactored code)

…token data

…rovider. IQSS#5974