Introduce entity_id_alternative_names Parameter for OpenID Federation

[peppelinux]

I propose the introduction of a new optional parameter, entity_id_alternative_names [ARRAY[str]], in the OpenID Federation Entity Configuration.

This parameter has an informative nature and enables the use of multiple unique entity identifiers, including EBSI and other DIDs, alongside the HTTPS identifiers currently used in OpenID Federation.

This parameter reinforces the role of the Federation Entity Configuration as a key point for discovery, while also providing flexibility. By allowing multiple identifiers, it can accommodate various identification systems, thereby enhancing interoperability.

[Tweeddalex]

Strongly support this! This change would also allow more flexibility in OIDF implementation profiles, allowing DID-based ecosystems such as EBSI, Swiss eID, GAN and Bhutan to map to OIDF as an overall framework.