Refactor Contract struct

[Neylix]

Description

To make it easy to understand and easier to use, many things has been refactored in contract workflow

• Worker module refactored (moving code around)
• Add new function in ContractFactory for test which adds the seed as ownerships as it should be in relad workflow
• Add the contract transaction in Contract struct has it is used at many places
• Remove ContractConstants struct, now this module is mainly a helper to convert transaction to constants
• Add new function Contract.sign_next_transaction so a Contract is responsible for it's own signature

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)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Test A
• Test B

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

[samuelmanzanera]

Nice refactor 🚀

[bchamagne]

LGTM, I'll do some functional tests monday

[bchamagne]

tested a few deployments:

• contract with trigger tx
• contract with trigger tx named
• contract with trigger interval

all is OK