Replace current Linked Verifiable Presentation implementation with identity_credential

[nanderstabel]

Description

Our current implementation of Linked Verifiable Presentation validation is custom-built and maintained in-house.

Recently, the identity.rs crate by the IOTA Foundation has been updated to support Linked Verifiable Presentations (see iotaledger/identity.rs#1398). This external crate is actively maintained and aligns with industry standards.

Depends on impierce/did-manager#31

Motivation

Outsourcing the implementation to a well-maintained external crate frees up our resources.

Resources

• Bump identity_ dependencies from 1.3 to 1.4 did-manager#31
• Linked Verifiable Presentations iotaledger/identity.rs#1398

To-do List

• Bump identity.rs dependencies to 1.4
• Utilize identity_credential's Linked VP implementation