Refactor contract ownerships

[Neylix]

Description

This PR improve the usability of the ownerships in the smart contracts. It also do some refactor about the contract constants.

• Contract seed ownership is not accessible in the variable contract (removing it before creating the constant)
• Contract ownerships are not anymore chained in the initial_tx (including the seed one)
• When signing the new contract transaction, the seed ownership is automatically added in first place (creating a new ownership with new encrypted_key)
• Owerships constant is now the same format as the Ownership module, used in contract.ownership variable. secrets, secret_keys and authorized_public_keys does not exist anymore
• Contract.add_ownership has a new api with secret and authorized_keys as a map of public_key => encrypted_key
• Contract.add_ownership keeps the order specified by the contract code
• Refactor constant module for legacy code as well
• Many tests has been updated to use TransactionFactory as the constants are now more strict (cannot have a nil address for example)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Units tests
Manual testing by creating contract and using ownerships

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[bchamagne]

• Playground is not working. Adaptation to do (I'll do it)

[bchamagne]

I tested it with playground