Support for dc+sd-jwt credentials

[Juliano1612]

Description

This adds end-to-end support for the dc+sd-jwt credential format (IETF SD-JWT VC, draft-ietf-oauth-sd-jwt-vc) to mobile-sdk-rs/kt/swift and SpruceKit Showcase app for both OID4VP and OID4VCI.

Other changes

• Renamed mdocDisplayName to credentialTypeDisplayName across both platforms since it now serves mdoc and dc+sd-jwt alike
• Added issuing_authority as a description fallback in GenericCredentialItemListItem

Optional section

• Reviewers, please pay special attention to the KB-JWT signing flow in ietf_sd_jwt_vc.rs. It uses a PresentationJwsSigner adapter that wraps the foreign PresentationSigner callback and converts DER signatures to raw R||S encoding
• PR exceeds 500 lines: 487 lines are the auto-generated (uniffi) and 533 lines are the new ietf_sd_jwt_vc.rs module. The remaining changes are integration changes

Tested

• Issued a dc+sd-jwt credential via OID4VCI
• Presented the credential via OID4VP with selective disclosure and KB-JWT
• Confirmed credential displays with correct title (from vct) and issuer (from issuing_authority) in the wallet list and OID4VP selector

[SeaSkyThe]

Tested with both Android and iOS with Animo Playground by Issuing and presenting a dc+sd-jwt Health ID and it works fine!

PS: Just a question, do we care about DC-API for this PR? I know iOS only accept mdocs, but I think Android would accept this format.