feat: goal field in invitations

Description

Adding a flag when invitation is created, if the flag is passed after connection is accepted, sender will send proof request to this connection

Related issues

• No related

Testing

Checklist

• I have updated the documentation (if necessary)
• I have added unit tests for new functionality (if applicable)
• My code follows the style guidelines of this project
• I have tested this code on my local machine before submitting this MR

Reviewers

@boyan.tsolov @alexey.lunin

Additional Notes