What type of PR is this?

• enhancement/feature

What this PR does / why we need it:

This PR manages the procedure to manage optional Enforcement of BlockChain Public Address Ownership prior to perform a binding.

• New API blockchain-public-address-validation is defined
• API blockchain-public-address is evolved to perform this additional enhanced validation in the bindign process

Which issue(s) this PR fixes:

Fixes #52

Special notes for reviewers:

• Pending to add description details an diagram for the info.description section
• Pending to look for a solution that makes the process more consistent avoiding to have some part of the flow outside "Service context" (part of signing a transaction)

Changelog input

 Enforcement of BlockChain Public Address Ownership

Additional documentation