Solves URI from contact point

[hcvdwerf]

Description:

This pull request introduces functionality to resolve URIs for contact details, specifically targeting the retrieval of more detailed information (e.g., ORCID). Previously, the contact["uri"] field defaulted to either a string or an empty value. With this update, we attempt to resolve the URI and retrieve associated metadata (e.g., VCARD.hasUID) when available.

Changes:

• Updated the _contact_details method to resolve URIs where applicable.
• For agents that are not URIRef, the system now attempts to fetch the VCARD.hasUID property to enrich the URI field.

Benefits:

• Improved Metadata Access: Resolving URIs, such as ORCIDs, allows us to retrieve richer and more accurate contact data (e.g., full names, affiliations, email addresses).

[amercader]

Wouldn't it make more sense to store VCARD.hasUID in a dedicated key like contact["identifier"]. I get that in the case of ORCID those happen to be URIs as well but that might not be always be the case right? e.g. if using a UUID