[Request] Add create_delegation_token_for_testing and destroy_delegation_token_for_testing to move DID package

## Description
Add create_delegation_token_for_testing and destroy_delegation_token_for_testing to move DID package.

## Motivation
Testing integrations of the IOTA::DID into smart contracts.

## Requirements
Write a list of what you want this feature to do.

1. It needs to allow us to create delegation_tokens for testing our contracts integrating IOTA::DID

## Are you planning to do it yourself in a pull request?

Yes