[DPP] Test end-to-end data exchange via postman - EDC v0.7.0

[saudkhan116]

Description

Update Postman collection to align with the EDC v0.7.0 and test the end-to-end data exchange journey. Update documentation if necessary

Update the DPP testdata

Acceptance Criteria

• [x] Working APIs from EDC
• [x] Perform end-to-end data exchange
• [x] Data provisioning tested using updated testdata updated