Standardized Contract Interface for Registry

[jac18281828]

A standardized contract interface will enable an implementation of proxy upgradability.

A contract interface provides the following benefits:

1. Provides guarantees to implementors about the underlying api and implementation of a contract they are using
2. The interface guarantees interoperability across contract versions so that upgradability is more seamless
3. Interfaces support modularity by defining the specific calls that must be part of a particular contract
4. Standardization and transparency are also introduced by a clean interface implementation
5. As mentioned above the interface will enable us to implement an upgradeable proxy contract with minimum dependencies
6. Interfaces may also promote security by reducing the attack surface of individual contract implementations