Issue Credential v1 and Present Proof v1

[dbluhm]

Opening early.

This PR moves ICv1 and PPv1 to a plugin.

This description will be updated with notes on any sharp edges encountered.

Plugin-ification

ICv1

• Credential revocation state used to get updated by the revocation manager by using the exchange record directly. Changed to trigger an event instead.

PPv1

• OOB depends on recalling pres ex records to populate attachments.
• Pres Exch handler depends on recalling pres ex records to retrieve proof request.

Features Lost

ICv1

• Attaching a credential offer to an OOB invitation. See this comment for thoughts on how to address this, if needed.

PPv1

• Attaching a presentation request to an OOB invitation. See this comment for thoughts on how to address this, if needed.

[jamshale]

This has become quite out of date with aca-py. It would still be a nice thing to accomplish but I'm going to close this. It will be another PR if it gets accomplished.