feat: add support to select Multiple cred-def and connections for verification(BE)

[vivekayanworks]

User story

• User should be able to select multiple connections while sending proof request, so that single proof request can be send to multiple connections.
• User should be able to create proof request with multiple credential definition.

Acceptance Criteria

• To add support for selection of multiple connections while verification

• [x] Changes in payload of POST /orgs/{orgId}/proofs Sends a proof request API.

• [x] There should be configurable maximum limit for multi-connection proof requests.(can be configurable in .env file).

• [x] User should be able to request proof for single and as well as multiple connection Id.

• [x] dto level validations for empty and required fields.

[pranalidhanavade]

Figma design and discussion is pending