feat: bootstrap identity Connection aggregate

[nanderstabel]

Description of change

There are two important changes in this PR:

1. The previous Connection aggregate in agent_verification is merged into the AuthorizationRequest aggregate.
2. A new Connection aggregate is added to the agent_identity domain, this also means that two new endpoints are opened:

• /connections both GET and POST: For GET additional query parameters can be added, for example: GET 'http://localhost:3033/v0/connections?did=did:example:123'
• GET /connections/:connection_id: To query a Connection by connection_id

Blocked by

• feat: add support for linked verifiable presentations #92
• feat: query aggregate instances by id #130

Links to any relevant issues

• Add Connection Aggregate #125

How the change has been tested

Added unit tests and added Postman Collection Requests

Definition of Done checklist

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• I have followed the contribution guidelines for this project
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• I have commented my code, particularly in hard-to-understand areas
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• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have successfully tested this change in a docker environment