Protocol-spec delegate registration

[pablitovicente]

Description

• Basic delegate registration acceptance
• Delegate registration for delegate who already exists
• Delegate registration with existing username
• Delegate registration with forbidden name

Motivation

Acceptance Criteria

JSON generator for:

• Basic delegate registration acceptance
• Delegate registration for user who already exists
• Delegate registration with existing username
• Delegate registration with forbidden name

Additional Information

Split from #4087

[pablitovicente]

I think Delegate registration with existing username is the same as Delegate registration for user who already exists maybe validation and error are slightly different in the implementation but the result from a chain perspective is the same.